Unlike (or un-dislike) a song

[JudahGabriel]

Currently, users can like or dislikes songs. However, there's no way to undo that operation. Clicking the like (or dislike) again should undo it.

This has been a common feature request. A listener recently wrote in saying,

How due I remove a song that I have saved in the "LIKES" area?

[JudahGabriel]

This is a duplicate of #57