mplayer: allow resuming from playlist

This includes the case of passing multiple files to command line
(internally this is the same as loading a playlist).

Resuming works by finding the first playlist entry that can be resumed.

Alternative implementations would be possible, such as hashing the
playlist contents. But this implementation is simpler, and doesn't have
the disadvantage that changes to the playlist (like appending entries)
will throw away the resume point.

This makes loading large playlists a bit slower, because it has to look
into ~/.mpv/watch_later/ for every entry. Loading a 15000 entries
playlist now increases from 150ms to 400ms. Considering you rarely load
playlists this big with mpv (because it's impractical considering the
terminal and non-GUI nature of the player), this is probably ok.

0 files changed, 0 insertions, 0 deletions