Adds KQueue support for Mac and BSD
Adds KQueue support for Mac and BSD

1. Adds netty Kqueue to the tcp transport.
2. Updates switch to check for:
  a. If "linux" and "amd64" and "netty.epoll.enabled" then use epoll.
  b. if "mac" and "x86_64" and "netty.kqueue.enabled" then use kqueue.
  c. if "freebsd" and "amd64" and "netty.kqueue.enabled" then use
     kqueue.
3. If none of the above default to NIO.

Anvil/riemann,riemann/riemann,riemann/riemann,aphyr/riemann,aphyr/riemann,Anvil/riemann