corpse_xname overhaul (trunk only)

Extend the capabilities of corpse_xname() so that various callers can
be simplified.  It can how handle an article prefix, effectively turning it
into corpse_doname() (not quite; still need doname() to see a count when
quantity is more than one, or to see bless/curse state).  It can also handle
inclusion of adjectives like "partly eaten" or "bite-covered".  For unique
monsters those come out in the form
  the Chromatic Dragon's partly eaten corpse
instead of the old
  partly eaten Chromatic Dragon corpse
[so wishing probably needs to be taught about potentially finding a monster
name before assorted adjectives such as blessed; also, name_to_mon() needs
to learn how to cope with the possessive suffix].

     A sizeable chunk of this patch deals with consolidating some of the
redundant "petrified by a cockatrice corpse" handling.  It may be possible
to consolidate all remaining instances together since they're quite similar,
but I didn't think about that until just now and I want to get this patch
over with.

src/do_wear.c

@@ -422,7 +422,7 @@ boolean voluntary;	/* taking gloves off on purpose? */
 
     if (touch_petrifies(&mons[obj->corpsenm]) && !Stone_resistance) {
 	You("now wield %s in your bare %s.",
-	    the(corpse_xname(obj, TRUE)),
+	    corpse_xname(obj, (const char *)0, CXN_ARTICLE),
 	    makeplural(body_part(HAND)));
 	Sprintf(kbuf, "%s gloves while wielding %s",
 		voluntary ? "removing" : "losing",