[tor-relays] Pretty sure our exit was being synflooded

[tor at t-3.net]

Thanks for the configuration suggestions. I intentionally set the 
conntrack limit high, maybe that  was not the best thing. I think I'll 
be putting it back.

Removing my extra IPTables code plus adding a reject for :8888 has 
made the exit behave properly again.

I wonder if the best possible course of action for this sort of thing 
would be within Tor itself. I don't know that it was a single client 
connection into Tor that was causing all this trouble, but maybe it 
was. One would think that one client should not be allowed to do 
something so severe with the TCP that it can single-handedly ruin a 
fast exit. Maybe a code change that forces a rate-limit that 
significantly slows down the ability of a single client to roll port 
scans should be considered by the devs.