CUtf8Utils: add "checkStrForUtf8()"
New UTF-8 string check, based on current Unicode standard (6.3), with three result values: plain ASCII, valid UTF-8, high ACSII.
fixed: We can't grab the duration from the streamdetails for stacks
Utf8Utils: add "isValidUtf8()" for convenient check for valid UTF-8 strings
Remove usage of CharsetConverter.isValidUtf8()
CharsetConverter: remove outdated "isValidUtf8()"
mpegts: do not set pts for missing dts in video streams

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffmpeg: add patch for backport: mpegts-do-not-set-pts-for-missing-dts
[nfs] - get rid of some CStdStrings in favour of std::string
[nfs] - better fix for fe97d68f87d6985b2bf57d8e942b36b5e7373066 - possibly fixes #14727 - thx jm for the idea :)
Merge pull request #3699 from arnova/streamdetail_stack_time_fix

fixed: We can't grab the duration from the streamdetails for stacks
[subtitles] check and get idx/sub pair when download.
[coreSubs] proper fix for cf85bdb , select services list if no subtitles are found
VideoInfoScanner::EnumerateEpisodeItem: don't use ToLower with UTF-8 strings, fixes #14728
Not needed as RegExps are done in caseless mode
Merge pull request #3764 from FernetMenta/mpegts

ffmpeg: backport mpegts fix for dts jumping backwards (trac 14622)
[lang] update of internal addon language files
[lang] update of core language files
[lang] update of skin.confluence language files
Merge pull request #3768 from taxigps/subtitle_addon

[subtitles] check and get idx/sub pair when download.
Merge pull request #3750 from Karlson2k/update_utf8_check

Update UTF-8 string check
[3D] Support switching to 3D resolutions

Include matching 3D flags (SBS/TAB) in the score of a resolution to switch to, to enable switching to 3d modes.
Also remove the old code that treated 3D modes differently when assigning a score.

I've also added a small weight to higher multiples of the desired framerate, so if display supports 30, 60 and 120Hz
and the video is 30fps then 30 will now be chosen rather than 120. This reduces the overhead of rendering the gui.