Make selector terr do the right thing for deities

Make selector terr do the right thing for deities

Commit db1ac2ed (v4.3.6) introduced a separate territory for deities,
and made the territory command use it by default for deities.  Deities
can still access the old default territory as territory number 0.

Selectors terr, terr0 (alias for terr), terr1, terr2, terr3 remained
unchanged, and a new selector dterr was created to let deities access
the deity territory.

Make selector terr virtual, so that it can do "the right thing", just
like the territory command: select territory 0 for mortals, and the
deity territory for deities.

Unfortunately, this requires us to switch xdump to use terr0 instead
of terr, because otherwise the deity xdump would contain the deity
territory twice, and territory 0 not at all.