compil against external libbluray
[omxplayer] Fix bad audio when sample_fmt is not reported on Open

For most codecs ffmpeg reports m_pCodecContext->sample_fmt on the avcodec_open2 call (e.g. ac3, dts, aac).
However some (PCM on dvd) report AV_SAMPLE_FMT_NONE on open, and only provide the correct format on decode.

This can cause the GetBitsPerSample call to change between open and decode and results in white noise when the word size is misinterpreted.

The simple solution is to always convert to float when open doesn't report the format and ensure GetBitsPerSample reports this value
[bluray] Allow retrieval of arbitrary items from a Blu-ray directory.
[ext. subs] Also check for external subtitles for Blu-ray disc image files.
Merge pull request #5204 from ace20022/bd_extsubs

[Fix] Make ext. subtitle loading work for Blu-ray disc image files and Blu-ray directories.
Merge pull request #4153 from alexmaloteaux/configure_libbluray_fix

compil against external libbluray
Merge pull request #5442 from popcornmix/omx_pcm_fix

[omxplayer] Fix bad audio when sample_fmt is not reported on Open