Introduce languages options to ULS

Default value of this option will be $.uls.data.autonyms().
It can be set to limit language selection to a set of languages.

Updated examples, used a config variable wgULSLanguages to set this.

Change-Id: Ia322cbdcdb14f08619d2e4df5b23e2702841d147

resources/js/ext.uls.init.js

@@ -66,6 +66,7 @@
 			onSelect: function( language ) {
 				changeLanguage( language );
 			},
+			languages: mw.config.get( 'wgULSLanguages' ),
 			searchAPI: mw.util.wikiScript( 'api' ) + "?action=languagesearch"
 		} );