2.91.4:
* Build:
  - Port to GtkStyleContext
  - Other GTK+ 3.x fixes

* Movie Player:
  - Remove the MythTV plugin (upstream is dead and UPnP works just as well)
  - Change the data paths in GSettings schemas
  - Lots of Python plugin fixes
  - Add a save file plugin
  - Fix a race condition when parsing multiple playlist entries
  - More GSettings fixes and cleanup
  - Use symbolic icons for the volume level
  - Fix plugin shutdown

* GStreamer backend:
  - Various drawing fixes

* Updated translations