fix BZ41474. Allows loading css files more than one time in old IE

Author: psavushchyk

css.js

@@ -74,7 +74,7 @@ define(function() {
   var ieCurCallback;
 
   var createIeLoad = function(url) {
-    curSheet.addImport(url);
+    curSheet.addImport(url + "?" + Math.random());
     curStyle.onload = function(){ processIeLoad() };
 
     ieCnt++;