libwebsockets

client fix for operation with libuv

 - libuv socket init binding was missing for client

 - failures like no ws protocol match are deferred until the
   ah is bound.  Check for these failures and make sure we
   tell the guy trying to set up the client connection the
   wsi is NULL if it has already failed and closed.

 - pfd.events was not initialized for the client init path

With this general client function is more robust but also
client connections work properly with libuv.

Signed-off-by: Andy Green <andy@warmcat.com>