SW-699: added documentation to RPCClientContextManagerMixin. renamed rpc_service.py module tp rpc.py, and it's classes to RPCClient and RPCService. Moved Request and ReplyMessage into rpc.py module. Mader MessageFactory and used it in FromBus and rpc.py

SW-699: refactored/simplified RPC as well. Refactored has_args/has_kwargs quirks in RequestMessage. Have one simple API.

SW-699: major refactoring of the messagebus's BusListener and Service. Together with Jan-David and Auke, I decided to only allow a single API for the service, and we chose the most commenly used API based on the MessageHandlerInterface which we refactored into the ServiceMessageHandler. TODO: add docstrings, fix tests, adapt all Services in lofar python code.

SW-699: fixed some typos. Made TemporaryQueue bindable to and exchange. Route RPC-ReplyMessages via exchange to temporary reply queue

SW-699: major rewrite of FromBus/ToBus, AbstractBusListener and RPC/Service based on kombu/rabbitmq. This allows us to use a single lofar exchange (multiple exchanges are still allowed), and using auto-generated designated queues with subject based routin_keys.

SW-699: Make notifications unconfigurable, greatly reducing complexity of the higher abstraction layers.

SW-699: Use a single broker and bus (exchange), and make service names unconfigurable (fixed in Service and RPC). Greatly reduces configuration size.

SW-657: added connection error handling + auto reconnect. Limited the number of threads for the buslisteners because of proton multithreading issues

SW-657: Use scu001/199 directly for LCS/Messaging/python, to avoid relying on qpid infrastructure for our services.

SW-657: number of threads needs to be 1 because of the way we use proton, otherswise one thread can receive a message and another thread can ack it, and then mayhem starts

SW-657: added todo about reconnect on proton._exceptions.ConnectionException, and assert on improper threads administration

SW-658: needed to refactor parts of the FromBus/ToBus because connections were not released. Took the opportunity to factor out common behaviour into abstract super class.

SW-610: fixed messagebus test which failed if ran in parallel in multiple builds-with-tests. The problem was a too largs messagebody filling the broker queue. Reduced the bodies size to a more real life value.

SW-516: fixed (de)desrialization of datetimes and large strings in messages now that we're using python3 and proton

SW-516: remove 'options' from messagebus classes, as these were qpid options, and we're using proton now. At this moment there is no need for such options. These can be added later when needed.

SW-516: added new class TemporaryQueue which can be used when a temporary-auto-delete-queue is needed, like for example in the tests.