Update to reveal.js 4.1.2 (#136)

- New tools/ script to manually keep step for updates
- Plugins are all updated
- Template update following latest Pandoc version
- updated README for documentation
- Help page updated 
- See other change in NEWS file
diff --git a/inst/reveal.js-4.1.2/plugin/zoom/plugin.js b/inst/reveal.js-4.1.2/plugin/zoom/plugin.js
new file mode 100644
index 0000000..0d4624d
--- /dev/null
+++ b/inst/reveal.js-4.1.2/plugin/zoom/plugin.js
@@ -0,0 +1,279 @@
+/*!
+ * reveal.js Zoom plugin
+ */
+const Plugin = {
+
+	id: 'zoom',
+
+	init: function( reveal ) {
+
+		reveal.getRevealElement().addEventListener( 'mousedown', function( event ) {
+			var defaultModifier = /Linux/.test( window.navigator.platform ) ? 'ctrl' : 'alt';
+
+			var modifier = ( reveal.getConfig().zoomKey ? reveal.getConfig().zoomKey : defaultModifier ) + 'Key';
+			var zoomLevel = ( reveal.getConfig().zoomLevel ? reveal.getConfig().zoomLevel : 2 );
+
+			if( event[ modifier ] && !reveal.isOverview() ) {
+				event.preventDefault();
+
+				zoom.to({
+					x: event.clientX,
+					y: event.clientY,
+					scale: zoomLevel,
+					pan: false
+				});
+			}
+		} );
+
+	}
+
+};
+
+export default () => Plugin;
+
+/*!
+ * zoom.js 0.3 (modified for use with reveal.js)
+ * http://lab.hakim.se/zoom-js
+ * MIT licensed
+ *
+ * Copyright (C) 2011-2014 Hakim El Hattab, http://hakim.se
+ */
+var zoom = (function(){
+
+	// The current zoom level (scale)
+	var level = 1;
+
+	// The current mouse position, used for panning
+	var mouseX = 0,
+		mouseY = 0;
+
+	// Timeout before pan is activated
+	var panEngageTimeout = -1,
+		panUpdateInterval = -1;
+
+	// Check for transform support so that we can fallback otherwise
+	var supportsTransforms = 	'WebkitTransform' in document.body.style ||
+								'MozTransform' in document.body.style ||
+								'msTransform' in document.body.style ||
+								'OTransform' in document.body.style ||
+								'transform' in document.body.style;
+
+	if( supportsTransforms ) {
+		// The easing that will be applied when we zoom in/out
+		document.body.style.transition = 'transform 0.8s ease';
+		document.body.style.OTransition = '-o-transform 0.8s ease';
+		document.body.style.msTransition = '-ms-transform 0.8s ease';
+		document.body.style.MozTransition = '-moz-transform 0.8s ease';
+		document.body.style.WebkitTransition = '-webkit-transform 0.8s ease';
+	}
+
+	// Zoom out if the user hits escape
+	document.addEventListener( 'keyup', function( event ) {
+		if( level !== 1 && event.keyCode === 27 ) {
+			zoom.out();
+		}
+	} );
+
+	// Monitor mouse movement for panning
+	document.addEventListener( 'mousemove', function( event ) {
+		if( level !== 1 ) {
+			mouseX = event.clientX;
+			mouseY = event.clientY;
+		}
+	} );
+
+	/**
+	 * Applies the CSS required to zoom in, prefers the use of CSS3
+	 * transforms but falls back on zoom for IE.
+	 *
+	 * @param {Object} rect
+	 * @param {Number} scale
+	 */
+	function magnify( rect, scale ) {
+
+		var scrollOffset = getScrollOffset();
+
+		// Ensure a width/height is set
+		rect.width = rect.width || 1;
+		rect.height = rect.height || 1;
+
+		// Center the rect within the zoomed viewport
+		rect.x -= ( window.innerWidth - ( rect.width * scale ) ) / 2;
+		rect.y -= ( window.innerHeight - ( rect.height * scale ) ) / 2;
+
+		if( supportsTransforms ) {
+			// Reset
+			if( scale === 1 ) {
+				document.body.style.transform = '';
+				document.body.style.OTransform = '';
+				document.body.style.msTransform = '';
+				document.body.style.MozTransform = '';
+				document.body.style.WebkitTransform = '';
+			}
+			// Scale
+			else {
+				var origin = scrollOffset.x +'px '+ scrollOffset.y +'px',
+					transform = 'translate('+ -rect.x +'px,'+ -rect.y +'px) scale('+ scale +')';
+
+				document.body.style.transformOrigin = origin;
+				document.body.style.OTransformOrigin = origin;
+				document.body.style.msTransformOrigin = origin;
+				document.body.style.MozTransformOrigin = origin;
+				document.body.style.WebkitTransformOrigin = origin;
+
+				document.body.style.transform = transform;
+				document.body.style.OTransform = transform;
+				document.body.style.msTransform = transform;
+				document.body.style.MozTransform = transform;
+				document.body.style.WebkitTransform = transform;
+			}
+		}
+		else {
+			// Reset
+			if( scale === 1 ) {
+				document.body.style.position = '';
+				document.body.style.left = '';
+				document.body.style.top = '';
+				document.body.style.width = '';
+				document.body.style.height = '';
+				document.body.style.zoom = '';
+			}
+			// Scale
+			else {
+				document.body.style.position = 'relative';
+				document.body.style.left = ( - ( scrollOffset.x + rect.x ) / scale ) + 'px';
+				document.body.style.top = ( - ( scrollOffset.y + rect.y ) / scale ) + 'px';
+				document.body.style.width = ( scale * 100 ) + '%';
+				document.body.style.height = ( scale * 100 ) + '%';
+				document.body.style.zoom = scale;
+			}
+		}
+
+		level = scale;
+
+		if( document.documentElement.classList ) {
+			if( level !== 1 ) {
+				document.documentElement.classList.add( 'zoomed' );
+			}
+			else {
+				document.documentElement.classList.remove( 'zoomed' );
+			}
+		}
+	}
+
+	/**
+	 * Pan the document when the mosue cursor approaches the edges
+	 * of the window.
+	 */
+	function pan() {
+		var range = 0.12,
+			rangeX = window.innerWidth * range,
+			rangeY = window.innerHeight * range,
+			scrollOffset = getScrollOffset();
+
+		// Up
+		if( mouseY < rangeY ) {
+			window.scroll( scrollOffset.x, scrollOffset.y - ( 1 - ( mouseY / rangeY ) ) * ( 14 / level ) );
+		}
+		// Down
+		else if( mouseY > window.innerHeight - rangeY ) {
+			window.scroll( scrollOffset.x, scrollOffset.y + ( 1 - ( window.innerHeight - mouseY ) / rangeY ) * ( 14 / level ) );
+		}
+
+		// Left
+		if( mouseX < rangeX ) {
+			window.scroll( scrollOffset.x - ( 1 - ( mouseX / rangeX ) ) * ( 14 / level ), scrollOffset.y );
+		}
+		// Right
+		else if( mouseX > window.innerWidth - rangeX ) {
+			window.scroll( scrollOffset.x + ( 1 - ( window.innerWidth - mouseX ) / rangeX ) * ( 14 / level ), scrollOffset.y );
+		}
+	}
+
+	function getScrollOffset() {
+		return {
+			x: window.scrollX !== undefined ? window.scrollX : window.pageXOffset,
+			y: window.scrollY !== undefined ? window.scrollY : window.pageYOffset
+		}
+	}
+
+	return {
+		/**
+		 * Zooms in on either a rectangle or HTML element.
+		 *
+		 * @param {Object} options
+		 *   - element: HTML element to zoom in on
+		 *   OR
+		 *   - x/y: coordinates in non-transformed space to zoom in on
+		 *   - width/height: the portion of the screen to zoom in on
+		 *   - scale: can be used instead of width/height to explicitly set scale
+		 */
+		to: function( options ) {
+
+			// Due to an implementation limitation we can't zoom in
+			// to another element without zooming out first
+			if( level !== 1 ) {
+				zoom.out();
+			}
+			else {
+				options.x = options.x || 0;
+				options.y = options.y || 0;
+
+				// If an element is set, that takes precedence
+				if( !!options.element ) {
+					// Space around the zoomed in element to leave on screen
+					var padding = 20;
+					var bounds = options.element.getBoundingClientRect();
+
+					options.x = bounds.left - padding;
+					options.y = bounds.top - padding;
+					options.width = bounds.width + ( padding * 2 );
+					options.height = bounds.height + ( padding * 2 );
+				}
+
+				// If width/height values are set, calculate scale from those values
+				if( options.width !== undefined && options.height !== undefined ) {
+					options.scale = Math.max( Math.min( window.innerWidth / options.width, window.innerHeight / options.height ), 1 );
+				}
+
+				if( options.scale > 1 ) {
+					options.x *= options.scale;
+					options.y *= options.scale;
+
+					magnify( options, options.scale );
+
+					if( options.pan !== false ) {
+
+						// Wait with engaging panning as it may conflict with the
+						// zoom transition
+						panEngageTimeout = setTimeout( function() {
+							panUpdateInterval = setInterval( pan, 1000 / 60 );
+						}, 800 );
+
+					}
+				}
+			}
+		},
+
+		/**
+		 * Resets the document zoom state to its default.
+		 */
+		out: function() {
+			clearTimeout( panEngageTimeout );
+			clearInterval( panUpdateInterval );
+
+			magnify( { x: 0, y: 0 }, 1 );
+
+			level = 1;
+		},
+
+		// Alias
+		magnify: function( options ) { this.to( options ) },
+		reset: function() { this.out() },
+
+		zoomLevel: function() {
+			return level;
+		}
+	}
+
+})();
diff --git a/inst/reveal.js-4.1.2/plugin/zoom/zoom.esm.js b/inst/reveal.js-4.1.2/plugin/zoom/zoom.esm.js
new file mode 100644
index 0000000..27c0921
--- /dev/null
+++ b/inst/reveal.js-4.1.2/plugin/zoom/zoom.esm.js
@@ -0,0 +1,4 @@
+/*!
+ * reveal.js Zoom plugin
+ */
+var e={id:"zoom",init:function(e){e.getRevealElement().addEventListener("mousedown",(function(o){var n=/Linux/.test(window.navigator.platform)?"ctrl":"alt",i=(e.getConfig().zoomKey?e.getConfig().zoomKey:n)+"Key",d=e.getConfig().zoomLevel?e.getConfig().zoomLevel:2;o[i]&&!e.isOverview()&&(o.preventDefault(),t.to({x:o.clientX,y:o.clientY,scale:d,pan:!1}))}))}},t=function(){var e=1,o=0,n=0,i=-1,d=-1,s="WebkitTransform"in document.body.style||"MozTransform"in document.body.style||"msTransform"in document.body.style||"OTransform"in document.body.style||"transform"in document.body.style;function r(t,o){var n=y();if(t.width=t.width||1,t.height=t.height||1,t.x-=(window.innerWidth-t.width*o)/2,t.y-=(window.innerHeight-t.height*o)/2,s)if(1===o)document.body.style.transform="",document.body.style.OTransform="",document.body.style.msTransform="",document.body.style.MozTransform="",document.body.style.WebkitTransform="";else{var i=n.x+"px "+n.y+"px",d="translate("+-t.x+"px,"+-t.y+"px) scale("+o+")";document.body.style.transformOrigin=i,document.body.style.OTransformOrigin=i,document.body.style.msTransformOrigin=i,document.body.style.MozTransformOrigin=i,document.body.style.WebkitTransformOrigin=i,document.body.style.transform=d,document.body.style.OTransform=d,document.body.style.msTransform=d,document.body.style.MozTransform=d,document.body.style.WebkitTransform=d}else 1===o?(document.body.style.position="",document.body.style.left="",document.body.style.top="",document.body.style.width="",document.body.style.height="",document.body.style.zoom=""):(document.body.style.position="relative",document.body.style.left=-(n.x+t.x)/o+"px",document.body.style.top=-(n.y+t.y)/o+"px",document.body.style.width=100*o+"%",document.body.style.height=100*o+"%",document.body.style.zoom=o);e=o,document.documentElement.classList&&(1!==e?document.documentElement.classList.add("zoomed"):document.documentElement.classList.remove("zoomed"))}function m(){var t=.12*window.innerWidth,i=.12*window.innerHeight,d=y();n<i?window.scroll(d.x,d.y-14/e*(1-n/i)):n>window.innerHeight-i&&window.scroll(d.x,d.y+(1-(window.innerHeight-n)/i)*(14/e)),o<t?window.scroll(d.x-14/e*(1-o/t),d.y):o>window.innerWidth-t&&window.scroll(d.x+(1-(window.innerWidth-o)/t)*(14/e),d.y)}function y(){return{x:void 0!==window.scrollX?window.scrollX:window.pageXOffset,y:void 0!==window.scrollY?window.scrollY:window.pageYOffset}}return s&&(document.body.style.transition="transform 0.8s ease",document.body.style.OTransition="-o-transform 0.8s ease",document.body.style.msTransition="-ms-transform 0.8s ease",document.body.style.MozTransition="-moz-transform 0.8s ease",document.body.style.WebkitTransition="-webkit-transform 0.8s ease"),document.addEventListener("keyup",(function(o){1!==e&&27===o.keyCode&&t.out()})),document.addEventListener("mousemove",(function(t){1!==e&&(o=t.clientX,n=t.clientY)})),{to:function(o){if(1!==e)t.out();else{if(o.x=o.x||0,o.y=o.y||0,o.element){var n=o.element.getBoundingClientRect();o.x=n.left-20,o.y=n.top-20,o.width=n.width+40,o.height=n.height+40}void 0!==o.width&&void 0!==o.height&&(o.scale=Math.max(Math.min(window.innerWidth/o.width,window.innerHeight/o.height),1)),o.scale>1&&(o.x*=o.scale,o.y*=o.scale,r(o,o.scale),!1!==o.pan&&(i=setTimeout((function(){d=setInterval(m,1e3/60)}),800)))}},out:function(){clearTimeout(i),clearInterval(d),r({x:0,y:0},1),e=1},magnify:function(e){this.to(e)},reset:function(){this.out()},zoomLevel:function(){return e}}}();export default function(){return e}
diff --git a/inst/reveal.js-4.1.2/plugin/zoom/zoom.js b/inst/reveal.js-4.1.2/plugin/zoom/zoom.js
new file mode 100644
index 0000000..686a548
--- /dev/null
+++ b/inst/reveal.js-4.1.2/plugin/zoom/zoom.js
@@ -0,0 +1,4 @@
+!function(e,o){"object"==typeof exports&&"undefined"!=typeof module?module.exports=o():"function"==typeof define&&define.amd?define(o):(e="undefined"!=typeof globalThis?globalThis:e||self).RevealZoom=o()}(this,(function(){"use strict";
+/*!
+	 * reveal.js Zoom plugin
+	 */var e={id:"zoom",init:function(e){e.getRevealElement().addEventListener("mousedown",(function(t){var n=/Linux/.test(window.navigator.platform)?"ctrl":"alt",i=(e.getConfig().zoomKey?e.getConfig().zoomKey:n)+"Key",d=e.getConfig().zoomLevel?e.getConfig().zoomLevel:2;t[i]&&!e.isOverview()&&(t.preventDefault(),o.to({x:t.clientX,y:t.clientY,scale:d,pan:!1}))}))}},o=function(){var e=1,t=0,n=0,i=-1,d=-1,s="WebkitTransform"in document.body.style||"MozTransform"in document.body.style||"msTransform"in document.body.style||"OTransform"in document.body.style||"transform"in document.body.style;function r(o,t){var n=l();if(o.width=o.width||1,o.height=o.height||1,o.x-=(window.innerWidth-o.width*t)/2,o.y-=(window.innerHeight-o.height*t)/2,s)if(1===t)document.body.style.transform="",document.body.style.OTransform="",document.body.style.msTransform="",document.body.style.MozTransform="",document.body.style.WebkitTransform="";else{var i=n.x+"px "+n.y+"px",d="translate("+-o.x+"px,"+-o.y+"px) scale("+t+")";document.body.style.transformOrigin=i,document.body.style.OTransformOrigin=i,document.body.style.msTransformOrigin=i,document.body.style.MozTransformOrigin=i,document.body.style.WebkitTransformOrigin=i,document.body.style.transform=d,document.body.style.OTransform=d,document.body.style.msTransform=d,document.body.style.MozTransform=d,document.body.style.WebkitTransform=d}else 1===t?(document.body.style.position="",document.body.style.left="",document.body.style.top="",document.body.style.width="",document.body.style.height="",document.body.style.zoom=""):(document.body.style.position="relative",document.body.style.left=-(n.x+o.x)/t+"px",document.body.style.top=-(n.y+o.y)/t+"px",document.body.style.width=100*t+"%",document.body.style.height=100*t+"%",document.body.style.zoom=t);e=t,document.documentElement.classList&&(1!==e?document.documentElement.classList.add("zoomed"):document.documentElement.classList.remove("zoomed"))}function m(){var o=.12*window.innerWidth,i=.12*window.innerHeight,d=l();n<i?window.scroll(d.x,d.y-14/e*(1-n/i)):n>window.innerHeight-i&&window.scroll(d.x,d.y+(1-(window.innerHeight-n)/i)*(14/e)),t<o?window.scroll(d.x-14/e*(1-t/o),d.y):t>window.innerWidth-o&&window.scroll(d.x+(1-(window.innerWidth-t)/o)*(14/e),d.y)}function l(){return{x:void 0!==window.scrollX?window.scrollX:window.pageXOffset,y:void 0!==window.scrollY?window.scrollY:window.pageYOffset}}return s&&(document.body.style.transition="transform 0.8s ease",document.body.style.OTransition="-o-transform 0.8s ease",document.body.style.msTransition="-ms-transform 0.8s ease",document.body.style.MozTransition="-moz-transform 0.8s ease",document.body.style.WebkitTransition="-webkit-transform 0.8s ease"),document.addEventListener("keyup",(function(t){1!==e&&27===t.keyCode&&o.out()})),document.addEventListener("mousemove",(function(o){1!==e&&(t=o.clientX,n=o.clientY)})),{to:function(t){if(1!==e)o.out();else{if(t.x=t.x||0,t.y=t.y||0,t.element){var n=t.element.getBoundingClientRect();t.x=n.left-20,t.y=n.top-20,t.width=n.width+40,t.height=n.height+40}void 0!==t.width&&void 0!==t.height&&(t.scale=Math.max(Math.min(window.innerWidth/t.width,window.innerHeight/t.height),1)),t.scale>1&&(t.x*=t.scale,t.y*=t.scale,r(t,t.scale),!1!==t.pan&&(i=setTimeout((function(){d=setInterval(m,1e3/60)}),800)))}},out:function(){clearTimeout(i),clearInterval(d),r({x:0,y:0},1),e=1},magnify:function(e){this.to(e)},reset:function(){this.out()},zoomLevel:function(){return e}}}();return function(){return e}}));