R1049 - various wand of digging bugs

R1049 - various wand of digging bugs
- Breaking wand of digging dug through rock which should be undiggable.
Checks assumed pits would never show up in solid rock.
- Breaking wand of digging near shop walls wouldn't anger the shopkeeper
Checks assumed pits would never show up in walls, also, added a special
case to pay_for_damage to handle the case where you're falling thru and
can't be asked to pay.
- Shop walls wouldn't be restored if there are pits in the way.
Checks assumed pits would never show up in walls.
- If there was a hole outside the shop, you could kick stuff out of the
door into the hole without shopkeeper noticing.  Added the missing check.