Multiplayer lobby based on the XmPP protocol. Special thanks to Philip, alpha123, scythetwirler, and anyone else who has helped build, debug or test the lobby.

git-svn-id: http://svn.wildfiregames.com/public/ps/trunk@14098 3db68df2-c116-0410-a063-a993310a9797
Fix error that slipped into the lobby commit.

git-svn-id: http://svn.wildfiregames.com/public/ps/trunk@14099 3db68df2-c116-0410-a063-a993310a9797
Merge 'remotes/trunk'