Cleanup PeasActivatable's init
Cleanup PeasActivatable's init

The function should be a static function. Also, it
will only ever be called once so there is no need
for doing the check/set initialized dance.
gregier/libpeas,Distrotech/libpeas,GNOME/libpeas,Distrotech/libpeas,gregier/libpeas,gregier/libpeas,chergert/libpeas,Distrotech/libpeas,gregier/libpeas,chergert/libpeas,GNOME/libpeas,chergert/libpeas