Open source wall scheduling

[jmccarten-wetafx]

Currently there is no sharable scheduler for wall training/inference.

In tandem with the shared scheduler we should also add a mechanism for basic general execution using OpenCue/Deadline.

This would open up wall training to the public.

[jmccarten-wetafx]

The proposal from Sony Imageworks is to use OpenCue as the OSS implementation for the wall.

This would sit on top of the scheduler classes and be shared between inference & training.