Support for all Link types

Added the missing ```sp_linktype``` entries (added in SPOTIFY_API_VERSION 5). Tests didn't seem necessary.

Note I screwed up the branch and the first couple of commits are unnecessary for this pull request (I didn't know how to undo them, reverting was my best guess) so could you please cherry pick the right ones?
* https://github.com/kingosticks/pyspotify/commit/2f956eb9fcb27a4f37e82d6e97b4045858e6936c
* https://github.com/kingosticks/pyspotify/commit/93b1228550ed43522685c08a5ff95e0c37e28c6a
* https://github.com/kingosticks/pyspotify/commit/1a44a3a7afa0addb36e6619c35673f8b938b4b42