using #name to call a floor object

using #name to call a floor object

Implement Boudewijn's suggestion that #name be extended to allow naming
something of the floor.  I'm sure he wants this so that he can avoid
picking up gray stones, but it's something I started to implement years
ago (probably at an earlier suggestion from him...) and then forgot all
about.

This changes the #name menu to be
   m - a monster
   i - a particular object in inventory
   o - the type of an object in inventory
   f - the type of an object upon the floor
   d - the type of an object on discoveries list
   a - record an annotation for the current level
   What do you want to name?
with the i and o choices omitted when inventory is empty.  If the
'lootabc' option is set it will use a through f instead, but then the
last three entries change letters when inventory is empty.  'y' and 'n'
are still accelerators (effectively hidden choices) for the i and o
entries, corresponding to the answers for the 3.4.3 and earlier "name
an individual object?" prompt.

The floor choice asks you to pick a location.  If you pick yourself,
then the top object of the pile underneath you is targetted.  Otherwise,
the target must be an object glyph, and the object must have its dknown
bit set, so have previously been seen up close or revealed via blessed
potion of object detection.  To make it be more useful, targetting an
object on an adjacent square will set the dknown bit.  (Just the top
object if there is a pile there.)  There's no cockatrice corpse touch
check since you aren't actually touching anything, just looking.

The setting of dknown bit for an adjacent object has been extended to
the '/' and ';' commands for examining things on the screen as well.
It's only done for adjacent spots you actively select, not all 8 spots
around you.