Ensure that the Syncer listens on all interesting updates (added
compareAndSwap and compareAndDelete).

Previously the Controller would be left in a bad state on a master ->
slave transition.

Proxied connections to Icecast are now handled with a simple TCP
proxy that can shutdown each direction independently. Fixes some
connection leaks.

Adds detailed information about the transcoding hierarchy and parameters.

The Stop() method on the liquidsoap controller could have been called
multiple times.