zmq connector fixes

couple of fixes here that retry creation of socket if context fails (which it can fail and recover without issue)

take out sleep when host lookup fails, we should have a sleep free gem now :)
(sleep was really just there to delay a little, but is un-needed)

add a recoverable zmq check that can be caught an recovered from when sockets don't respond, really to be used when we set zmq timeouts (which should probably be a minor release not a patch)

let the local_queue in the broker go to 4 entries instead of 1
no, I left the linger from a previous PR that was too invasive, I can remove the linger constant until we need that PR