Enable fallback TS discont logic for Blu-rays

This ensures a badly authored Blu-ray does not cause serious playback
issues. While it is possible that this logic will not provide 100% smooth
timestamps, it'll ensure that playback at least continues normally.
Don't sent stream discontinuities for Blu-rays

Blu-rays may have their timestamps jumbled up sometimes, but the stream
stays compatible. No need to flush.