Make looting less tedious

I've seen complaints how looting containers is tedious, and
since multiple containers in the same location are now (and have
been for a while) handled with a menu, the yes-no-quit prompt
for a single container doesn't really mean anything.

Remove that prompt, and remove the "open carefully" message too,
so when you're looting a location with a single container, the
command will drop straight into the loot-in-out -menu.  Also
adjust one looting message to explicitly mention the container
if there are other objects on top of it.

Removing the prompt means you can't loot a saddle from a tame
monster with plain loot when standing on a container - you need
to prefix the loot command with 'm' prefix in that case.

doc/fixes3-7-0.txt

@@ -795,6 +795,8 @@ make ravens oviparous
 thrown items can get stuck in webs
 engraving with Fire Brand burns the text on the floor and does not
 	dull the artifact
+make looting less tedious by getting rid of a y/n prompt making the command
+	go directly into the loot-in-out -menu
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository