stone-to-flesh on corpse-wielding golem (trunk only)

stone-to-flesh on corpse-wielding golem (trunk only)

     A couple of months ago Michael forwarded a thread from the newsgroup
about how wielding a cockatrice corpse without gloves while polymorphed
into something capable of that would leave you wielding that corpse
bare-handed if you changed form, turned to stone, then got life-saved.
That got fixed; the corpse becomes unwielded.  However, one of the
messages in that described a different bug:  if you were wielding such a
corpse as a stone golem and cast stone-to-flesh at yourself, you would
continue to wield it bare-handed as a flesh golem.  This makes you revert
back to stone golem once the first transformation has finished.

     This also fixes an attribute exercising bug in polymon().  It was
being done after the polymorph was completed, so the attempt to exercise
Con didn't do anything because exercise() of anything other than Wis has
no effect when the hero is polymorphed.