This patch extends perlin noise to operate in 1D, 2D, 3D, and 4D
space. The noise code has also been refactored to be more readable.
The Color output and distortion patterns changed, so this patch
breaks backward compatibility. This is due to the fact that we
now use random offsets as noise seeds, as opposed to swizzling
and constants offsets.
Reviewers: brecht, JacquesLucke
Differential Revision: https://developer.blender.org/D5560
