Modernize ES for-loops and remove problematic for-in loops

This slightly modifies the behaviour of errors (see init.js)

Change-Id: I1aab691d5b7e8167b6213378bdd9139c133202cd
diff --git a/dev/js/src/match.js b/dev/js/src/match.js
index 92062cc..7ce2652 100644
--- a/dev/js/src/match.js
+++ b/dev/js/src/match.js
@@ -85,10 +85,9 @@
       else {
 
         // Iterate over allowed match terms
-        for (var i in _matchTerms) {
-          var term = _matchTerms[i];
+        _matchTerms.forEach(function(term) {
           this[term] = match[term] !== undefined ? match[term] : undefined;
-        };
+        }, this);
       };
       
       this._avail = {