add subtitles extension list and allow to remove it using URIUtils::RemoveExtension
(cherry picked from commit 02841320c2a9e863330fc6580ee1ff42ad133519)
add method converting language string to 2char code
passed language string could be either other code or full language name
(cherry picked from commit 4b9cc5daded526d70ec2def1fae4aeedb83bb65f)
add CUtil::GetExternalStreamNameAndLangFromFilename method to extract stream language and name from filename
(cherry picked from commit 5789502a521d6bfee6897926fb7f7fe9c6ce0a86)
use CUtil::GetExternalStreamNameAndLangFromFilename to determine external subtitles's language and name
(cherry picked from commit cd657c4356a3254f1559c75187e98af1a2fe31bd)
dvdplayer: update current video settings when changing setting subtitles stream to be sure we keep it synced (similiar to what we already do when we show/hide subtitles)
(cherry picked from commit 6322da6ead66907f0c248b493ea5dbe291e67044)
add VideoPlayer.SubtitlesLanguage infolabel that returns full language name of current subtitles, "unknown" localized string or empty string if subtitles are disabled or video isn't playing currently
Adapt DVDFileInfo so that it reads the language from external subtitles files.
changed VIDEOPLAYER_SUBTITLES_LANG number to 309