Add external .idx as external subtitle for MediaInfoWrapper.cs.
Merge branch 'master' of https://github.com/MediaPortal/MediaPortal-1 into BUG-4434-Skip_Previous_does_not_work_in_some_cases
Merge branch 'BUG-4434-Skip_Previous_does_not_work_in_some_cases'
Merge branch 'master' of https://github.com/MediaPortal/MediaPortal-1 into BUG-4427-MyPictures_while_music_is_playing_can_failed_with_Video_running
Merge branch 'BUG-4427-MyPictures_while_music_is_playing_can_failed_with_Video_running'
Merge remote-tracking branch 'remotes/origin/BUG-4261-Subtitles_issues_v1.3.0.0_(DVBSub3.ax)'
Merge remote-tracking branch 'remotes/origin/BUG-4430-Fontengine_changes_cause_CTD_XP'
Merge remote-tracking branch 'remotes/origin/BUG-4426-Missing_idx_subtitle_format_display_OSD_Mediainfo'
Merge remote-tracking branch 'remotes/upstream/master' into 1.4.0Fork_SEB_New_Master