Compositor redesign

Overview
The goal of the project is upgrade the core of the compositor to sustain current and future technological and artist’s demands. The current compositor has known limitations in both area’s. Francois Tarlier and Math Ebb has done a very good job on the artist side. Some of these wishes are very valuable and have big impacts on the core. Some of these wishes have been added to the proposal to make sure that the nodes don’t need to be re-done in a later stage.