Maximum buffering time (AOUT_MAX_PREPARE_TIME) is increased to 2
seconds, consistent with increases in audio hardware buffer sizes.
In practice however, this is bound to the input PTS delay.

Maximum advance time is updated accordingly (+ 1 second).

Lip desynchronization tolerance is segregated, following EBU R37:
 - 40 ms (as before) maximum audio advance
 - 60 ms maximum audio delay.