edited the logic a little bit

[cm86]

Hello,
this is my first time i'm writing public in python.
But i tried to edit your script a little bit.
Because of if you always delete and create the playlist new, the watch status is gone, i have modified the script.

• outsourcing of playlist to file (mcuchronologicalplaylist.txt) --> make editing easier
• if there is no playlist with the name you choosed --> it creates the playlist
• if there is already a playlist with the same name --> it looks inside the playlist and gives you the choice
• -> if you have more items in you library you can add them and check the order
• -> if you have the wrong content in your playlist you can remove them and check order
• -> if the playlist is up to date you can check the order

[PJnes]

Thanks a lot for this PR. There's quite a bit here, will need some time to review it!