Initial support for webfonts in MobileFrontend

Written in pair-programming with Ryan Kaldari.

This adds a version of webfonts initialization that is stripped
of any smart features. It only loads the basic jquery.webfonts
library and the fonts repository in a way that is usable
with the MobileFronted extension.

It is completely disabled by default.

It can be enabled by setting
$wgULSMobileWebfontsEnabled = true;
and even then it will only be enabled for users
who opted in for the mobile beta mode.

Change-Id: I488e411232a1192bbf46ae5675c701366bda9a3e

UniversalLanguageSelector.hooks.php

@@ -344,4 +344,21 @@ class UniversalLanguageSelectorHooks {
 
 		return true;
 	}
+
+	/**
+	 * Add basic webfonts support to the mobile interface (via MobileFrontend extension)
+	 * Hook: EnterMobileMode
+	 * @param MobileContext $context
+	 * @return bool
+	 */
+	public static function onEnterMobileMode( $context ) {
+		global $wgULSEnable, $wgULSMobileWebfontsEnabled;
+
+		// Currently only supported in mobile Beta mode
+		if ( $wgULSEnable && $wgULSMobileWebfontsEnabled && $context->isBetaGroupMember() ) {
+			$context->getOutput()->addModules( 'ext.uls.webfonts.mobile' );
+		}
+
+		return true;
+	}
 }