change #vanquished from wizard mode to normal play

Make the existing '#vanquished' command be available during regular
play, with M-V bound to it.  'm #vanquished' or 'm M-V' brings up
the sorting menu that you get when answering 'a' rather than 'y' at
the end-of-game "disclose vanquished creatures?" prompt.

The original #vanquished came from slash'em, where it was available
in normal play.  When added to nethack, it was put in as wizard-mode-
only. I added the sorting capability several years ago.

The chosen sort is remembered and re-used if not reset but only for
the remainder of the current session.  It probably ought of become
a run-time option so be settable in advance and across sessions but
I haven't done that.

dat/hh

@@ -140,6 +140,7 @@ M-s   sit       sit down
 M-t   turn      turn undead if role allows that
 M-T   tip       upend a container to dump out its contents
 M-u   untrap    untrap something
+M-V   vanquished list number and type of vanquished monsters
 M-v   version   print compile time options for this version
 M-w   wipe      wipe off your face
 M-X   explore   switch from regular play to non-scoring explore mode

dat/wizhelp

@@ -19,7 +19,6 @@ Debug-Mode Quick Reference:
 #stats          == show memory statistics
 #terrain        == show current level (more options than in normal play)
 #timeout        == look at timeout queue and hero's timed intrinsics
-#vanquished     == disclose counts of dead monsters sorted in various ways
 #vision         == show vision array
 #wizborn        == show monster birth/death/geno/extinct stats
 #wizcast        == cast any spell