This adds the capability that the recorder can propagate when it's
ready. This happends by providing a small http server which response
with an `OK` under [localhost:11411](http://localhost:11411).

Closes #153

Closes: #139 #103 #146 #152 #132

update documentation for environment variables and
add `clock_pattern` to the example config

Closes #147

Closes #27

Signed-off-by: Daniél Kerkmann <d.kerkmann@opentalk.eu>

This adds the ability to read multiple sinks from the configuration.
This allows the user to stream to multiple sinks concurrently.

This is related to #62

Signed-off-by: Daniél Kerkmann <d.kerkmann@opentalk.eu>

Adding an rtmp sink allows us to stream to a rtmp server.