fix brocken DEBUG define
Update TODO

Remove stuff thats been done or obsolete
Do not get stuck processing HTTP requests, found by Thorduri
Don't stop passing the accept lock even when workers are very busy.

If a worker reached worker_max_connections and it was its turn to
grab the accept lock it would've gotten stuck and no new connections
would be handled even if other workers would be less busy.

Instead, we now skip the lock if we're too busy and pass it along
in the hopes other workers are less busy.
Add example module cruft to gitignore
tiny style nit
Small note on accept locking semantics