When looking at name_to_mon() to teach it how to cope with possessive
suffices, I discovered that it already knows how. But while looking at
it, I remembered a newsgroup complaint from a while back by someone who
accidentally committed suicide by attempting to genocide "master mindflayers"
(when he meant "master mind flayers"). name_to_mon() didn't recognize that
misspelling but it did match "master" as a role title. Unfortunately for
the player, his character was a monk; the game allowed him to genocide his
own role and he died. That's kind of harsh for such a likely misspelling.
(I don't think a monk is very likely to ever use "master thief" as a mistake
for "master of thieves", but catch that one too just in case. Conversely,
recognize "master of assassins" as an alternate for "master assassin".)
Also, wishing for "the <something>" strips off "the" and finds (or not)
<something>, but genociding didn't. You could specify "a wolf" to wipe out
all wolves, but "the wolf" yielded "such creatures don't exist", and ^G had
similar unfriendly behavior. This extends name_to_mon() to handle it.