Allow passing data-properties to menu items.

Usage:

menu: [
{ title: 'item a', data: { id: 123, 'some-other-property': 42, action:
... }
]

which adds
data-id="123" data-some-other-property="42"
to the a-element.

Author: francisrath

jquery.ui-contextmenu.js

@@ -306,6 +306,9 @@ $.extend($.moogle.contextmenu, {
 			if(entry.disabled){
 				$parentLi.addClass("ui-state-disabled");
 			}
+			if($.isPlainObject(entry.data)){
+				$a.data(entry.data);
+			}
 		}
 		return $a;
 	},