Landing pull request 389. Null elements in clone to avoid memory leak in IE. Fixes #9341.

More Details:
 - https://github.com/jquery/jquery/pull/389
 - http://bugs.jquery.com/ticket/9341

src/manipulation.js

@@ -582,6 +582,8 @@ jQuery.extend({
 			}
 		}
 
+		srcElements = destElements = null;
+
 		// Return the cloned set
 		return clone;
 	},