Adding of depthfield version of sphere cube

* Added version using depth fields
Improvements in gitignore
Improvements within gitignore
Modifications to match project goals

* Modified code to match project goals
* Ignoring of libvsr library files
Merge branch 'master' of https://github.com/sosterwalder/bzg1310

Conflicts:
	.gitignore
	sphere_cube_versor/bin/sphere_cube_vsr