kernel - Major MP work on kq and signal processing
* Remove the global kq_token and move to a per-kq and per-kqlist
pool token. This greatly improves postgresql and mysql performance
on MP systems.
* Adjust signal processing tokens to be per-LWP instead of per-PROC.
Signal delivery still utilizes a per-proc token but signal distribution
now uses a per-LWP token, which allows the trap code to only lock the
LWP when checking for pending signals.
This also significantly improves database performance.
* The socket code also now uses only its per-socket pool token instead
of kq_token for its kq operations. kq handles its own tokens.