Abrandoned/thread backtraces

1. Alpha several methods primarily in the zmq connector
2. Elevate the zmq broker polling milliseconds on the select call to an ENV var "PB_ZMQ_BROKER_POLLING_MILLISECONDS"
3. Add SIGTRAP to the trapped signals in zmq server so `kill -s TRAP pid` will log the backtrace of each thread
4. Fix "bug" with stats that always logs the first server as the server chosen from the client side when multiple servers are avail, the stats host/port needed to be reset if another server is chosen by the beacons, ping port (maint) or the first alive load balancing

@localshred 
this is a style change, please revert it unless there's a good reason to keep it