inotify, zeroconf, dirstate

[Matt Mackall]

I've fixed a few bugs in the inotify extension. If you were having
trouble with this before, it may be better. If you're a Linux user and
you haven't tried it, please give it a spin, especially if you've got a
large repo.

I've also fixed a few bugs in zeroconf. I've gotten some mixed reports.
Patrick tells me it works out of the box on at least his Windows box,
and I've heard it works on several Debian machines. More testers needed,
please.

I've also added a C parser for the dirstate, so that's now about 3x
faster (though not as fast as I'd hoped). I've also made minor
performance improvements to diff, status, and manifest parsing. Enjoy.

-- 
Mathematics is the supreme nostalgia of our time.