fix #H4414 - orcs vs elven gear

fix #H4414 - orcs vs elven gear

I considered several potential interactions for orcs with elven
armor (and elves with orcish armor), such as longer wear/unwear
delay, reduced AC, or reduced magic cancellation/negation.  None
of them seemed worth doing.  In the end I just went with lembas
wafer tweaks:  new message when orc hero eats one, reduced nutrition
for that combination, different new message when elf hero eats one,
and increased nutrition for this combination.  Also, less increased
nutrition when a dwarf hero eats a cram ration.

I'm not particularly happy with either of the new messages, and
changing nutrition on the fly may lead to bugs.