Regenerate keyframe index for MPEG2->MPEG2 transcoding

[Aaron McCarthy <mccarthy.aaron@…>]

Two problems.

After transcoding mpeg2 recordings the regenerated keyframe index is immediately deleted by the jobqueue code.

Secondly, on some setups the recordedmarkup table contains MARK_GOP_START entries instead of MARK_GOP_BYFRAME. The keyframe index is regenerated if MARK_GOP_BYFRAME entries are not found. This is required on at least one PVRx50 setup.

[cpinkham]

(In [7263]) JobQueue, mythtranscode, and logging related modifications.

Main patches by Robert Tsai & Aaron McCarthy with a little merging by me.

• Add logging to display mythtranscode's filespace savings.

• Logging cleanup and addition of subtitle (if present) in some places.

• Regenerate MARK_GOP_BYFRAME index on recordings that only have MARK_GOP_START since the transcoder needs MARK_GOP_BYFRAME.

• Cleanup old keyframe/gop index in mythtranscode rather than having the JobQueue do it. The JobQueue has no way of knowing whether mythtranscode generated a MPEG2 file and corresponding MARK_GOP_BYFRAME entries or if it generated a MPEG4/RTJPEG file with the seektable in the nuppel file, so it only makes sense to move this logic into mythtranscode.

Closes #325 and closes #237.

[cpinkham]

(In [7264]) Transcoding patch (for real this time).

This is part of Aaron McCarthy's patch that I forgot to apply as part of my last commit. This commit should really close #237.