limit postings by count

[Jimjjewett]

Place a limit on the number of postings/day before the list
becomes temporarily moderated. (mlist.emergency gets
set and EmergencyHold added to the processors.)

Ideally, there would also be a separate per-poster limit
before the individual became temporarily moderated.

Reason: If one (or even several) individuals sets up a
bad .vacation responder or succumbs to a virus, the list
may soon be swamped with junk traffic. Better to shut it
down than to swamp all readers.

(Why yes, I am on a pair of lists sending out new digests
every 5 minutes because of a .vacation loop problem. In
this case, it would be enough to stop posts from this
individual, but I realize that may not always be the case.)

[http://sourceforge.net/tracker/index.php?func=detail&aid=820728&group_id=103&atid=350103]