fix --time-limit

It got broken in several ways by the streaming seeking optimisations
around version 8.20201007.

Moved time limit checking out of the matcher, which was a hack in the
first place. So everywhere that uses Limit.getMatcher needs to check
time limit. Well, almost everywhere. Command.Info uses it, but it does
not make sense to time limit getting info. And Command.MultiCast uses it
just to build up a list of files that then get passed to a command, so
it would never have hit the timeout in a useful way.

This implementation is a little more expensive when at time limit than
necessary, since it continues seeking only to discard everything after the
time limit. I did try making it close the file handles to force a faster
shutdown, but that didn't work and hung. Could certianly be improved
somehow, but seeking is probably not the expensive bit when a time limit
is hit, so this seems acceptable for now.