Synchronize Playlist with File

[puehri]

It would be nice, if i can sync a playlist with a file.
First I import a playlist (screenshot001/002/003).
After a few days i want to add some new tracks to the playlist and easlily add it to the active playlist. I´m saving the playlist via Ctrl+s to Best.m3u.
Then it would be nice, if there´s a button to sync the playlist (screenshot004) with the playlistfile (screenshot004_2).

This means it loads data from the new edited file and replaces the old playlist.

Automatically load an edited file would also be nice