Add/Remove from library keys.

[ryantheleach]

It would be great to get add / remove hotkeys added, so that when listening to radio I can save a song I like, or when listening to library, evict a song I never want to hear again.

[nachmore]

This would require giving Toastify access to your user account, i.e. can't be done via interaction with the client. Will look at this for the future.