I scripted a GEGL fade-out and transition for Gimp

As a 'proof of concept' I wrote a batch script with GEGL to make fade-ins, fade-outs and transitions using both. 

Simple fade to black done in Gimp and GEGL.

Details and the script are here:

https://www.gimp-forum.net/Thread-I-made-a-fade-in-fade-out-effect-for-Gimp-with-GEGL