Update SCSS to module system (fixes #266)

Change-Id: I2387ef49dadaeac0f62620e0c803df12dad42cf8
diff --git a/dev/scss/base/menu.scss b/dev/scss/base/menu.scss
index 993b237..433f69e 100644
--- a/dev/scss/base/menu.scss
+++ b/dev/scss/base/menu.scss
@@ -1,7 +1,7 @@
 @charset "utf-8";
-@import "choose";
-@import "lengths";
-@import "icons";
+@use "choose";
+@use "lengths";
+@use "icons";
 
 /**
  * Definitions for menu design.
@@ -34,18 +34,18 @@
   
   > li,
   > span.non-item:not(.active) {
-    @include choose-item;
+    @include choose.choose-item;
   }
 
   > li,
   > span.non-item:not(:empty) {
-    @include choose-item;
-    box-shadow:  $choose-box-shadow;
+    @include choose.choose-item;
+    box-shadow:  choose.$choose-box-shadow;
     cursor:      pointer;
-    padding:     $item-padding;
+    padding:     lengths.$item-padding;
     white-space: normal;
     border: {
-      width:        $border-size;
+      width:        lengths.$border-size;
       bottom-width: 0px;
       top-width:    0px;
       style:        solid;
@@ -59,10 +59,10 @@
   div.lengthField {
     border: {
       color: transparent;
-      width: $border-size;
+      width: lengths.$border-size;
     }
     overflow: hidden;
-    padding: $item-padding;
+    padding: lengths.$item-padding;
     padding-top: 0;
     padding-bottom: 0;
     span {
@@ -87,7 +87,7 @@
     transition:       opacity .5s ease 1s;
 
     > span {
-      @include choose-active;
+      @include choose.choose-active;
       position: absolute;
       display:  block;
       right:    0;
@@ -101,12 +101,12 @@
     }
 
     &.active > span {
-      @include choose-hover;
+      @include choose.choose-hover;
     }
 
     > div {
-      @include choose-item;
-      box-shadow: $choose-box-shadow;
+      @include choose.choose-item;
+      box-shadow: choose.$choose-box-shadow;
       position:   absolute;
       right:      0;
       width:      10px;
@@ -138,17 +138,17 @@
   > li {
     &:first-of-type {
       border-top: {
-	      width:        $border-size;
-	      left-radius:  $standard-border-radius;
-	      right-radius: $standard-border-radius;
+	      width:        lengths.$border-size;
+	      left-radius:  lengths.$standard-border-radius;
+	      right-radius: lengths.$standard-border-radius;
       }
     }
 
     &:last-of-type {
       border-bottom: {
-	      width:        $border-size;
-	      left-radius:  $standard-border-radius;
-	      right-radius: $standard-border-radius;
+	      width:        lengths.$border-size;
+	      left-radius:  lengths.$standard-border-radius;
+	      right-radius: lengths.$standard-border-radius;
       }
     }
     mark {
@@ -161,18 +161,18 @@
 
   > li.active,
   span.non-item.active {
-    @include choose-active;
+    @include choose.choose-active;
   }
 
   > li:hover,
   span.non-item:hover {
-    @include choose-hover;
+    @include choose.choose-hover;
   }
 
   span.non-item {
     border: {
-      radius: $standard-border-radius;
-      width:  $border-size !important;
+      radius: lengths.$standard-border-radius;
+      width:  lengths.$border-size !important;
     }
   }
   
@@ -216,7 +216,7 @@
     &:not(.no-more):before {
       position:    absolute;
       font-family: "FontAwesome";
-      content:     $fa-up;
+      content:     icons.$fa-up;
       right:       .5em;
       top:         .4em;
     }
@@ -225,7 +225,7 @@
     &:not(.no-more):before {
       position:    absolute;
       font-family: "FontAwesome";
-      content:     $fa-down;
+      content:     icons.$fa-down;
       right:       .5em;
       bottom:      .4em;
     }
@@ -246,7 +246,7 @@
     content: '';
   }
   > li.active:hover {
-    @include choose-remove;
+    @include choose.choose-remove;
   }
 }