add a closure around Font so we can hide helper functions in it

fonts.js

@@ -84,7 +84,8 @@ var Fonts = {
  *   var type1Font = new Font("MyFontName", binaryFile, propertiesObject);
  *   type1Font.bind();
  */
-var Font = function(aName, aFile, aProperties) {
+var Font = (function () {
+  var constructor = function(aName, aFile, aProperties) {
     this.name = aName;
 
     // If the font has already been decoded simply return it
@@ -146,7 +147,7 @@ var Font = function(aName, aFile, aProperties) {
    * But at the moment it allows to develop around the TrueType rewriting
    * on the fly without messing up with the 'regular' Type1 to OTF conversion.
    */
-Font.prototype = {
+  constructor.prototype = {
     name: null,
     font: null,
     mimetype: null,
@@ -566,6 +567,8 @@ Font.prototype = {
     }
   };
 
+  return constructor;
+})();
 
 /**
  * FontsUtils is a static class dedicated to hold codes that are not related