* Use threads for delegation. Now `run_once` lock before `accept` not `select`
* Add support to use master proxy within proxy pool plugin. When used, proxy pool plugin will be a no-op for the master node
* Fix acceptor tests now that mask is being used
* Use `cached_property` for web server routes
* Use `select(timeout=1)` otherwise acceptor wont join if total blocking
* mypy, flake, doc spell fixes
* R0205: Class `cached_property` inherits from object, can be safely removed from bases in python3 (useless-object-inheritance)
Abhinav Singh