polled socket system. This much more cleanly and efficiently integrates peer
(and other server to server) connections into the normal server I/O framework
and should also eliminate for good the annoying server hangs that result when
our old blocking client I/O threads got their pants wedged.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5510 542714f4-19e9-0310-aa3c-eee0fc999fb1
Michael Bayne