OTHER: Try to fix travis, still no gtk found.
OTHER: Normalize 'from' to 'on' for album in playlist.
OTHER: Fix equalizer size and fallback handling.
OTHER: Increase Icon size.
OTHER: Migrate toolbar to GtkHeaderBar.
OTHER: Cleanup NowPlaying.

Removed the idle timeout since it never worked as intended and
fixing it in a platform independent way was kind of impossible.

Fullscreen is now activated via menu and playback accelerators
are now working in fullscreen mode. A bit of a hack since I
couldn't figure out how to propagate the keyevent to the
main window accelerator group. Should be fixed some day.
OTHER: Remove broken accelerator for connect dialog.
OTHER: Add accelerators to playback button tooltips.
OTHER: Fix typo in equalizer widget.