Adds a rough (non-working) outline of the ZeroMQ jobmanager bridge for external job management
Finishes out implementation of push block notifications for main chain.

* Separates out polling block height from generating new jobs periodically
* Toggles block polling when using push block notifications
Internal bridge replacement for regular jobmanager, using zeromq. Will work in conjunction with the standalone jobmanager
~15x speedup on pusing new work from a block to users, along with minor fixes
* Fixed an import loop from central powerpool module
* Heavy code reduction and optimization in method of transmitting new block to clients
* Moved the "manager" file to be called "main" which makes a bit more sense
* Added some profiling utils
* Added a direct entry point for running with -OO for optimal speed