Enable the new WLM plugin for Kopete.

This new plugin replaces the MSN plugin and requires an external library
called libmsn which can be gotten from <a href="http://sourceforge.net/projects/libmsn">http://sourceforge.net/projects/libmsn</a>;
We're working towards a 0.4 release of that library but until then, please download the beta versions.

The new WLM plugin provides support for the MSNP15 protocol version and in general lays the groundwork for a better MSN plugin.

Thanks go to Tiago Salem Herrmann, Gustavo Boiko, and Roman Jarosz for doing all the heavy lifting.