major restructering of the front end test framework

tests/frontend/lib/jquery.iframe.js

@@ -0,0 +1,39 @@
+//copied from http://stackoverflow.com/questions/8407946/is-it-possible-to-use-iframes-in-ie-without-memory-leaks
+(function($) {
+    $.fn.purgeFrame = function() {
+        var deferred;
+
+        if ($.browser.msie && parseFloat($.browser.version, 10) < 9) {
+            deferred = purge(this);
+        } else {
+            this.remove();
+            deferred = $.Deferred();
+            deferred.resolve();
+        }
+
+        return deferred;
+    };
+
+    function purge($frame) {
+        var sem = $frame.length
+          , deferred = $.Deferred();
+
+        $frame.load(function() {
+            var frame = this;
+            frame.contentWindow.document.innerHTML = '';
+
+            sem -= 1;
+            if (sem <= 0) {
+                $frame.remove();
+                deferred.resolve();
+            }
+        });
+        $frame.attr('src', 'about:blank');
+
+        if ($frame.length === 0) {
+            deferred.resolve();
+        }
+
+        return deferred.promise();
+    }
+})(jQuery);