clearing no_charge bit for containers

clearing no_charge bit for containers

[I can't get access to my mail at present, but `cvs update' shows
that there aren't any patch notification messages pending for me.]

     Extend a pre-3.4.3 fix--for objects picked up in an untended shop--
to container contents.  Without it, dropping a bag or box in a tended shop
and declining to sell it, then picking it back up after the shop has become
untended (shk killed or evicted) would leave the contents with no_charge
set.  After that it could be sold in another tended shop, picked back up
for free, then kept or sold a second time.  (Picking it back up in the
tended shop would clear the bit; afterwards it behaved normally.  And it's
not something prone to abuse; if you can make a tended shop become untended
you really don't need to sell stuff twice.  But it'd be noticeably wrong if
anyone ever stumbled across it.)