TpBaseContactList: emit GroupsRemoved and GroupsChanged when removing a group
TpBaseContactList: emit GroupsRemoved and GroupsChanged when removing a group

Also emit debug messages when doing so.

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib