Only boolean properties are usable with TS

The Xclass Extension of matchcondition is not the best solution. After a hook is inserted to this class, it will be possible to extend this class in a safe and more powerful way.

Caching has not been activated due to incompatibilities with PHP <4.2 (stable brand of Debian is PHP 4.1 at the time of writing this document). Since parsing the XML file is very time consuming the cache functionalities will have to be activated in future releases, when I either upgraded my PHP install or find a way to get around the 'var_export' function used to build the cache files.