WIP: SSE-enabled backend based on webactors
This is highly WIP.
https://github.com/puniverse/comsat/pull/75 is of interest because for now we have to enable websockets even though we don't use them. Also https://github.com/puniverse/comsat/issues/76 because for now we need to use reflection to access that information.
There is also more to do and it will be usable for #3 (closed)