* Remove support for legacy endpoint based signaling and make source-name signaling as the only signaling mode. The legacy screensharing mode will no longer be supported. The client will still be able to process remote presence sent in the old format to support interop with very old mobile clients and jigasi that do not support source-name signaling.
* remove code related to presenter mode.

Avoid needing an external dependency.

Since the order of the ssrcs in the json-encoded message is not guaranteed to be in the correct SIM/FID order, log all the ssrcs.