Fixes playback of some streaming media.

For some HTTP media, ffurl_read returns 0 in the number of bytes read instead of EOF. So exit early otherwise it would loop forever
(cherry picked from commit 2ed284bca5cea3fb4de51eac890d2c56bb9e0e12)
Allow the use of cutlists with --video and --mpeg2
(cherry picked from commit 59f336996dc3fd27129a806fe480a04de6b9aae5)

Refs #11614
DVD PTS discontinuities are now handled by 'flattening' the timecodes of incoming packets. This prevents AVFormatDecoder getting stuck buffering video frames when the timecodes jump backwards.

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>
(cherry picked from commit b6c0ec5529d8b921a846c38b5d6afeb06a4d5671)

Refs #11371
MythWeather Environment Canada Parser update

Fixes #11623

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>
(cherry picked from commit 34620185a9a5b832bcc9bb597e3afe0668fbee06)