part of issue #1463: // vs lootabc

Issue reported by ashleyharvey in a comment to issue #1463:  with the
'lootabc' option set, using the '/' command wouldn't accept a second
slash to look at things on the map (nor a question mark to type in
text to look up).

Not a bug since '//' is not documented as the way to look at the map
and '/a' works for lootabc, but '//' is useful so add support for it.

The '/' menu already uses 'y' and 'n' as unshown synonyms for looking
at the map and for looking up words.  Those now only work for the
'!lootabc' setting since lootabc can't assign multiple group
accelerators to the relevant choices.  Many of the other !lootabc
choice letters now work as unshown synonyms for lootabc choices, but
not all.  Feeding 'i' and 'e' to the menu as group accelerators would
interfere with using them as ordinary abc choices (at least for tty).

doc/fixes3-7-0.txt

@@ -1546,6 +1546,9 @@ objects are now accurately tracked as discovered even if not type-named nor
         formally identified (fixing some bugs in scroll writing, and making
         the discoveries list more accurate)
 you cannot sacrifice objects/corpses while stunned or confused
+'whatis' actions // and /? didn't work when the lootabc option was on, they
+	required /a and /c instead; add '/' and '?' as group accelerators so
+	that they work; /y and /n for them now only work when lootabc is off
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository