Code review comment for lp:~daschuer/mixxx/autodj

I agree that we could use descriptive icons for some of the player-like elements in AutoDJ, namely "Shuffle Playlist","Skip Next Track" and "Fade Now" to save some horizontal space for smaller skins.

Suggestion:
* Remove the "Multicolor-Gnome" icons and references and replace it with an existing icon as dummy (e.g. ic_library_autodj.png). I`ll extend our existing custom iconset for the new icons needed as well as the per-skin styling of the transition spinbox later on.
* Restore the default "Enable Auto DJ" button, we follow the "Call to action button" paradigm for main buttons in AutoDJ/Analyze/Recordings.