Investigate methods for dynamic playback delay adjustment

[thomaseleff]

Currently, the audera streaming system implements a constant playback delay, audera.PLAYBACK_DELAY. However, a constant playback delay does not respond to changes in network reliability, which leads to cases of inconsistent playback. Experiment with solutions that dynamically update audera.PLAYBACK_DELAY on the server-side, that allow for the application to increase delay when the reliability of the network decreases and decrease delay when reliability increases.