Add note about updating async support to include zmq.green.
Explicitly shutdown the logging system.
Add injector script to inject logging calls into the ZMQ pipe, for debug purposes.
Refactor logging system to support different formats (both serialization and encryption/signing of data):
* Add LogMessageHandler ABC to describe interface for handling an incoming log message
* Invert previous inheritance model, to support different message encoding handlers on top of ZMQ
* Add implementations of the Fernet and GCM authenticated encryption schemes
  * GCM handler expects an addition authkey_salt value to derive the key from the saved password
* Update logging daemon to support receiving messages from any of the 3 handlers
Erroneous docstring...