Currently entries in playlist files like m3u are first added to the
playlist, and then if they were relative paths the playlist file's
dirname is prepended to them.
Change it to directly add entries with the correct path. This will be
needed to normalize playlist entries as soon as they are added, else
normalization would prepend the working directory to entries with
relative paths.
demux_cue, demux_edl and demux_mkv_timeline don't need to be modified to
work with the next commit.
Guido Cella
2871471f31