This patch changes the 'fixinv' from boolean option to
Controls whether objects remember the inventory letters they
had, and how the inventory is reordered when picking up an
object. The possible values are:
For backward compatibility, no value needs to be specified
(which defaults to 'next'), or it can be negated (which
defaults to 'none').
- none - objects do not remember their letters, and empty places in
inventory are compacted away;
- next - objects remember their letters, but if the place is taken,
put the object to next free place.
- move - objects remember their letters, but if the place is taken,
move the object underneath to next free place.