When you're swallowed, an angry god trying to zap you will kill
the engulfer and hero gets credit (experience) and blame (possible
loss of luck and/or alignment if engulfer is peaceful or tame) for
the act. But hero didn't actually kill the critter, so don't
increment the kill counter that monitors pacifism.
I think there are other circumstances where hero gets credit and/or
blame for something he or she didn't directly do, but offhand I
can't think of them. They might warrant similar treatment.
Tidying of xkilled() triggered by malformed block comment which is
actually a hybrid of an end of line comment (the boulder one, not
the 'dest' parameter one)....