fix githib issue #108 - wishing for mimic corpse

fix githib issue #108 - wishing for mimic corpse

Fixes #108

"small"/"medium"/"large" prefix was being stripped off during wish
parsing so that it could be used to control glob size.  But those
are also prefixes for monster and/or object names.  Wishing for
"small mimic corpse" or "large mimic" corpse failed with "nothing
matching that description exists" when it tried to satisfy "mimic
corpse".  (Asking for "giant mimic corpse" worked as intended.)

Not mentioned in the report:  wishing for "large {dog, cat, kobold}
corpse" produced the corpse of corresponding normal sized critter
instead of that of a large one.

Noticed while testing the fix:  wishing for "glob" failed rather
than pick a random glob type.  Wishing for "glob of grey ooze"
failed even though "grey ooze" is recognized as a variant spelling
for the gray ooze monster.  Wishing for "<monster type> glob" also
failed even when the monster type was viable for globs.  This fixes
all of those even though no one will ever notice....

Wishing for "small box" (and "medium box") no longer yields a large
box, it fails with "nothing matching..." instead.  I was ambivalent
about the earlier change which had the unintended side-effect of
making them synonyms for "large box" so haven't tried to revive it.