revisit #H4083 - glob ID and merging

revisit #H4083 - glob ID and merging

Globs on the floor used different criteria (anything goes) than globs
in inventory (mostly requiring same ownership when in shops and same
curse/bless state--other stuff generally isn't applicable) when
deciding whether two globs should merge.  That was okay as long as
the globs on the floor were from being left behind when a pudding or
ooze was killed, but not if the player had picked some up, dipped
them in holy or unholy water, and dropped them again.  This changes
things so that globs on the floor use the same criteria as globs in
inventory when deciding whether to coallesce.

Also, my earlier fix was modifying globs in the mergeable() test (to
make bknown and rknown match) rather than during actual merge, which
would be a problem if the merger didn't take place for some reason.