Default to mov when audio is PCM

[mifi]

Many people are surprised because sometimes videos contain a PCM audio stream in an MP4 file. This is apparently non-compliant with MP4 but many cameras do it nonetheless. LosslessCut will fail if trying to export this. Because MP4 doesn't support PCM audio, while MOV does, I think we should default to MOV output format if PCM audio is detected and mp4 input format. Must check for pcm_s16be and the other flavors. See also 8e1ad81

Related:

• Videos from the Lumix FZ-2000 - cannot Export the cutted file #947
• Feature Request: Auto-set XAVC-S output container to MOV #367
• Support for PCM WAV audio format #476
• "Whoops! ffmpeg was unable to cut this video." Error #163

See also:

• https://stackoverflow.com/questions/17651975/unable-to-store-pcm-audio-in-mp4-container-file
• http://forum.doom9.org/archive/index.php/t-140877.html
• https://ffmpeg.org/pipermail/ffmpeg-user/2016-March/031300.html