Playlist saving and loading

[markjamesm]

• Implement a playlist save and load feature.

• Display the list of songs in the playlist in the GUI

[markjamesm]

Thinking of implementing this feature using the PlaylistsNet library to support M3U playlist files. Inside the MusicSharp TUI, there would need to be options to:

• Add files to a playlist.
• Remove files from a playlist.
• Load a playlist.

Note: See tmk907/PlaylistsNET#10 for a current minor issue involving an optional tag, and test before integrating this library into the project.

[markjamesm]

I actually ended up going with the ATL Dotnet library as it is more mature and offers better documentation. See this branch for progress:

https://github.com/markjamesm/MusicSharp/tree/playlists

[markjamesm]

Playlist loading has been implemented successfully.

The next step is to think about how playlist saving will work. Currently, if you open a playlist and then a new file, the new file doesn't get added to the existing playlist. Maybe it should, and users have the option to save a snapshot of the playlist in this state (using a dialog box)?