resumeReading
Lifts a pauseReading: the sender plays on, which for a live stream is the live edge, so the engine drops what it had buffered before the pause and plays what arrives from here (#441). Called on the demux lane, only after a pauseReading that answered true.
Return
true when a pause was lifted, false when there was none
Throws
when the sender or the connection refuses, for example because the server ended the session while the player was paused. The engine then opens the stream again, at the live edge. Defaulted to false, as pauseReading is.