load replaygain tags on mp4 style files
load tags when opening file so they are available when we try to read replaygain

provide a fallback file type to tagloader based on content

pass content type to DVDplayer for types that support tags, in order to set a fallback filetype
[vfs] remove win32 code from SmbFile.h/.cpp
[vfs] remove win32 code from SMBDirectory.cpp
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.
renderer: add underlying support for 16bit textures on gles
renderer: move UploadYV12Texture to same location as in GLES renderer

Simplifies diffing
renderer: match GLES UploadYV12Texture structure with GL version
renderer: calculate source rect on upload GLES:EGL/CVRef/MediaCodec
Utf8Utils: add "isValidUtf8()" for convenient check for valid UTF-8 strings
Remove usage of CharsetConverter.isValidUtf8()
CharsetConverter: remove outdated "isValidUtf8()"
[dxva] added dxva-hd renderer as alternative native dxva.
fixup! renderer: calculate source rect on upload GLES:EGL/CVRef/MediaCodec
renderer: factor out logic for upgrading GL format to 16bit
fixup! renderer: add underlying support for 16bit textures on gles
[subtitles] check and get idx/sub pair when download.
[lang] update of internal addon language files
[lang] update of core language files
[lang] update of skin.confluence language files