Docs and adjust the name used to reference libkqueue in traffic.lib.
Add accept filter support.

Initialize the accept filter or linux variant in a new init_listening_socket function and
expose access to SO_ACCEPTFILTER.

sockets_transit.set_accept_filter("httpready")

Currently, no error is thrown if this fails as it is not critical.
Forward declarations for when they're needed.
Fix ParseTuple and get rid of some warnings.