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

UniversalLanguageSelector.php

@@ -59,6 +59,7 @@ $wgHooks['BeforePageDisplay'][] = 'UniversalLanguageSelectorHooks::addModules';
 $wgHooks['PersonalUrls'][] = 'UniversalLanguageSelectorHooks::addTrigger';
 $wgHooks['SkinAfterContent'][] = 'UniversalLanguageSelectorHooks::addTemplate';
 $wgHooks['ResourceLoaderTestModules'][] = 'UniversalLanguageSelectorHooks::addTestModules';
+$wgHooks['ResourceLoaderGetConfigVars'][] = 'UniversalLanguageSelectorHooks::addConfig';
 $wgAPIModules['languagesearch'] = 'ApiLanguageSearch';
 $wgHooks['UserGetLanguageObject'][] = 'UniversalLanguageSelectorHooks::getLanguage';