fix #H7865 - shop prices for container contents

The recent attempt to have looking inside a container show shop
prices had multiple problems.  Worst one was showing shop prices as
if the hero would be buying for items already owned by the hero.
Item handling inside containers on shop floor was inconsistent:  if
shop was selling those items, they would include a price, but if not
selling--either already owned by hero or shopkeeper didn't care about
them--they were only marked "no charge" if hero owned the container.

This is definitely better but I won't be surprised if other obscure
issues crop up.  Gold inside containers on shop floor is always owned
by the shop (credit is issued if it was owned by the hero) but is not
described as such.

doc/fixes36.2

@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.223 $ $NHDT-Date: 1546655319 2019/01/05 02:28:39 $
+$NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.224 $ $NHDT-Date: 1546687293 2019/01/05 11:21:33 $
 
 This fixes36.2 file is here to capture information about updates in the 3.6.x
 lineage following the release of 3.6.1 in April 2018. Please note, however,
@@ -373,6 +373,11 @@ if bouldersym bug (via 'O', above) put a <NUL> ('\0') on the map, examining
 	"Alphabet soup: 'an("")'."
 wizard mode m^T, not selecting a teleport choice didn't teardown the menu
 	properly and could eventually lead to "No window slots!" panic
+when in a shop and using ':' to look inside a container in inventory, items
+	owned by hero showed price they'd be charged if hero was buying them
+when in a shop and using ':' to look inside a container on shop floor, items
+	that shopkeeper didn't care about weren't shown as "no charge" unless
+	the hero owned the container
 tty: turn off an optimization that is the suspected cause of Windows reported
 	partial status lines following level changes
 tty: ensure that current status fields are always copied to prior status