fix for #H9430 and github issue #1207 - gas clouds

Reported yesterday as issue #1207 by elunna and over four years ago
in #H9430:  monsters in gas clouds that should be shown by Warning
aren't.  And in some discussion of #H9430 back then:  monsters
adjacent to the hero while in gas clouds aren't shown on the map,
but combat and other interaction describes them as if they were.
There have been changes since then--to prevent seeing things on the
far side of gas clouds as if there were no clouds in the way--but
the basic problems with warning and adjacency weren't addressed.

This is a band-aid (tm) that probably makes things livable.  Don't
allow gas region display to override monsters that are sensed via
warning or when the hero is next to them.  That part doesn't work
correctly if the hero isn't blind and is inside the cloud while the
monster is adjacent but outside.  I think it will take more than a
band-aid to deal with that sensibly.

Closes #1207

doc/fixes3-7-0.txt

@@ -1861,6 +1861,11 @@ if an amulet of flying gets stolen while hero is over lava without other
 poison gas breath from green dragon or iron golem that hit and was reflected
 	left target enveloped in a gas cloud (reflection now takes precedence;
 	somewhat odd though: gas that misses still leaves target enveloped)
+Warning didn't show nearby monsters who were inside poison gas/steam/smoke
+	regions
+map didn't show adjacent monsters if they were inside a gas region unless
+	they were seen via telepathy or extended monster detection, but they
+	were described as if visible in messages (combat, for instance)
 
 
 Fixes to 3.7.0-x Platform and/or Interface Problems Exposed Via git Repository