Make sure forked process has stopped when deleting MythSystem

This forces a termination in a forked MythSystem process when the
MythSystem object is destroyed, preventing a situation where the private
internal object tries to access resources from the no-longer-existent
parent object.

Fixes #11412
(cherry picked from commit 9c51ad39a65eee7a3f985a127700fbc8473ffb4e)
Called methods against wrong object in destructor.

Refs #11412
(cherry picked from commit e1f14a5380886c6ddf95379341aa0f56481b7587)
Fix h.264 frame/keyframe identification in the player.

If a NAL unit that determines a frame start appears as the last NAL
unit in the packet, then the frame start is not identified until the
start of the next packet.  If this new packet has its own NAL unit
that determines a frame start, and that NAL unit is not at the end of
the packet, then only one frame start would be counted rather than
two.  This is fixed by returning the total number of frame starts,
rather than a bool.

In theory, the same problem could exist in the recorder, but it
appears that the packets in the original recording may have some
trailing NAL units that are stripped by the ffmpeg libraries when
assembling the packet for the player, causing the situation not to
occur.
(cherry picked from commit 86c22ed3d5c522bcecb88ecacd58104fc0dd6d8d)
Bump binary version after cherry picking 86c22ed3d5c522bcecb88ecacd58104fc0dd6d8d
MythArchive: update the encoding profiles to work with the current mythffmpeg

Refs #11299.

Signed-off-by: Stuart Auchterlonie <stuarta@squashedfrog.net>

(cherry picked from 5a0e83a20e8f75612b86fb56039b7803a11afd1b)
MythArchive: update mythburn.py to work with the updated encoding profiles

Refs #11299.

Signed-off-by: Stuart Auchterlonie <stuarta@squashedfrog.net>

(cherry picked from a784b93f1d1c6edbc0b47ac578def5d3275171a8)
MythArchive: update mythburn.py to work with the new mpeg2video codec name

Refs #11299.

Signed-off-by: Stuart Auchterlonie <stuarta@squashedfrog.net>

(cherry picked from 13c3035d1fed13a37c42d872b1f8dafb2e6f556f)
Make comparisons consistent

Refs #11299