pollfs: a naive filesystem for pollable objects

This patch set introduces a new file system for the delivery of pollable
events through file descriptors. To the detriment of debugability, pollable
objects are a nice adjunct to nonblocking/epoll/event-based servers.

Currently implemented waitable "objects" are: signals, futexes, ai/o blocks,
timers and fsync.

Very initial stage, it has only been slightly tested and isn't ready for prime.
The syscall wire up patches were skipped, the complete patch set can be found at:

http://haxent.com/~davi/pollfs/

Comments are welcome.

--
Davi Arnaut