Log Message:
libdvdnav: Update to 6.1.0

libdvdnav (6.1.0)
 * add a dvdnav_open2 API to setup a logging mechanism, similar to libdvdread
 * add a dvdnav_get_number_of_angles API
 * add a dvdnav_version API
 * rework the logs in the library and remove direct printf calls
 * handle out-of-order ADMAP entries blocking playback
 * fix crashes in dvdnav_describe_title_chapters in broken DVDs
 * cleanup old code and buildsystem