onSelect callback option for ULS

* Correct the dependencies for ext.uls.core, it need not depend on
mediawiki.Uri.
* Move the setlang function out of ULS core js.
* Add a callback function to the example.

Change-Id: Ie3598236b2a884580092194c57558ec109d20803

resources/ext.uls.init.js

@@ -19,6 +19,14 @@
 
 ( function( $ ) {
 	$( document ).ready( function() {
-		$( '.uls-trigger' ).uls();
+		$( '.uls-trigger' ).uls( {
+			onSelect : function( language ) {
+				var uri = new mw.Uri( window.location.href );
+				uri.extend( {
+					setlang : language
+				} );
+				window.location.href = uri.toString();
+			}
+		} );
 	} );
 } )( jQuery );