revived unicorn horns (trunk only)

revived unicorn horns (trunk only)

     Back in Nov'04, <Someone> pointed out that even with only 5%
chance for dropping a horn upon the death of a unicorn which has been
revived from corpse, it's still possible to produce a nearly unlimited
number of them for polypile fodder.  This bumps the chance for a horn up
to 50%, but flags the horn as coming from a revived corpse and makes such
horns be treated by polymoprh as if they're non-magic (which practically
guarantees that they'll poly into mundane tools instead of magic ones).