* Fixed XSS vulnerability introduced by r49833. Only pre-release versions of MediaWik...

* Fixed XSS vulnerability introduced by r49833. Only pre-release versions of MediaWiki were affected.
* Refactored the IE script entry point security check into WebRequest::isPathInfoBad(). Use the standard CGI variable PATH_INFO to do this check instead of the various potential non-standard solutions. Made the check fairly permissive to avoid a repeat of bug 13049 due to broken CGI setups especially with cgi.fix_pathinfo=0. This should theoretically be very portable and secure, but I have not tested it widely.
* Removed Chris Wrinn from the credits since his patch was wrong and has been removed.
* Made the error message more informative.