Renamed roster_jid_from_handle -> roster_barejid_from_handle
Renamed _roster_handle_set -> _roster_handle_push
Renamed handle, jid and resource in roster

Renamed to name, barejid and fulljid
Renamed roster_barejid_from_handle -> roster_barejid_from_name
Renamed roster_change_handle -> roster_change_name
Refactored roster push handling