C/#name menu, calling old discoveries [2 of 2] (trunk only)

Implement <Someone>'s menu-mode for #name, primarily because it
is the natural place to add [re]naming entries in the discoveries list,
something that was requested in the newsgroup ten or so years ago.  The
latter allows changing the type name of something which has previously
been named and is no longer being carried.

     This also makes the C command become a synonym for #name or vice
versa; one or the other could now be reassigned to something else.

dat/cmdhelp

@@ -21,7 +21,7 @@ b       Go southwest 1 space
 B       Go southwest until you are on top of something
 ^B      Go southwest until you are near something
 c       Close a door
-C       Call (name) a particular monster
+C       Call (name) a monster, an individual object, or a type of object
 d       Drop an item
 D       Drop specific item types
 e       Eat something
@@ -47,7 +47,7 @@ L       Go east until you are on top of something
 m       Followed by direction, move without picking anything up or fighting
 M       Followed by direction, move a distance without picking anything up
 n       Go southeast 1 space
-N       Go southeast until you are on something (if number_pad, name an object)
+N       Go southeast until you are on something (if number_pad is on, name)
 ^N      Go southeast until you are near something
 o       Open a door
 O       Show option settings, possibly change them
@@ -109,7 +109,7 @@ M-i     Invoke an object's special powers
 M-j     Jump to another location
 M-l     Loot a box on the floor
 M-m     Use a monster's special ability
-M-n     Name an item or type of object
+M-n     Name a monster, an individual object, or a type of object
 M-o     Offer a sacrifice to the gods
 M-p     Pray to the gods for help
 M-q     Quit