Redo how updates of permanent inventory window are suppressed during
restore. Reverses part of e9f1e03271
which included a simpler attempt to deal with this.
It looks like we should have been getting impossible "unpaid_cost:
object wasn't on any bill" but segfault was reported; I haven't tried
to figure out why. The band in xname() ought to be redundant now but
is included for bulletproofing.
777d9d922d