ie7 fixes: define indexOf, use charAt rather than [] to access string,

put try/catch around fn that was throwing errors.

lms/static/scripts/boxsizing.htc

@@ -85,7 +85,10 @@ function update(){
   }
   resizetimeout = window.setTimeout(function(){
     restore();
-    init();
+    try {
+        init();
+    }
+    catch (err) {}
     resizetimeout = null;
   },100);
 }