#39 Compute Voxelization Simplifications : WIP

- added new Compute Shader implementing many simplifications
- still WIP since Candidate voxel selection is not yet implemented
#26 Buttons / Sliders : GUI Frame WIP

- WIP on a Frame to the right of the window, used for buttons etc.
- WIP on a GUI Shader used for texture or simple color rendering
- Changed static value names to Upper-Case to look more pro