Clan invitation changes

This allows clan invitations to be sent in every zone that is not
considered a PvP zone.
Merge git://github.com/twostars/snoxd-koserver
BUGFIX : Defense skills now work, added SendUserStatusUpdate()

All stat modifying buffs should work now, SendUserStatusUpdate is added,
but not implemented into the skill system (yet).
Merge pull request #43 from maxmenten/master

Some fixes