Fixed full screen functionality for image module in HTMLModule.

TNL-265

common/lib/xmodule/xmodule/js/src/html/display.coffee

@@ -6,6 +6,8 @@ class @HTMLModule
     Collapsible.setCollapsibles(@el)
     if MathJax?
 	    MathJax.Hub.Queue ["Typeset", MathJax.Hub, @el[0]]
+    if setupFullScreenModal?
+      setupFullScreenModal()
 
   $: (selector) ->
     $(selector, @el)

common/lib/xmodule/xmodule/js/src/html/imageModal.js

@@ -1,6 +1,7 @@
-$(function() {
+var setupFullScreenModal = function() {
   
-  // Set up on page load
+  // Setup full screen image modal.
+  // Executed from HTMLModule in display.js.
   $("a.modal-content").each(function() {
     var smallImageObject = $(this).children();
     var largeImageSRC = $(this).attr('href');
@@ -106,4 +107,4 @@ $(function() {
       $(".wrapper-modal-image .image-content .image-controls .modal-ui-icon").toggleClass('is-disabled');
     }
   });
-});
+};