Prevent crashes due to regexp compilation errors

Page titles are now properly escaped using preg_quote() to prevent regexp
compilation errors if the title contains characters with special meanings in
regular expressions.

LinkTitles.php

@@ -49,7 +49,7 @@
     'name'           => 'LinkTitles',
     'author'         => '[https://www.mediawiki.org/wiki/User:Bovender Daniel Kraus]', 
     'url'            => 'https://www.mediawiki.org/wiki/Extension:LinkTitles',
-    'version'        => '2.2.1',
+    'version'        => '2.2.2',
     'descriptionmsg' => 'linktitles-desc'
     );