Issue reported by elunna: the definition of the Mitre of Holiness
specifies that carrying it should confer fire resistance but that
didn't work.
The Mitre's definition (added in 3.1.0) has always included that,
but such a capability had never been implemented. Wearing it didn't
confer fire resistance either--its definition doesn't bother to
specify a 'defend' attribute since the 'carry' one should cover that.
This adds carrying capability for damage types fire, cold, sleep,
disintegration, electrity, poison, acid, and petrification. Fire is
still specified by the Mitre; none of the others are currently used.
Fixes#1362
a311f4b467