Blender Git Loki

Cycles: move hair particle settings to scene context

Since the beginning of times hair settings in cycles were global for
the whole scene but were located in the particle context. This causes
quite some trickery to get shots set up for the movies here in the
studio by forcing artists to create dummy particle system to change
settings of hair on the shot.

While ideally this settings should be properly become per-particle
system for the time being it will save sweat and blood to move the
settings to scene context.

Reviewers: brecht

Subscribers: jtheninja, eyecandy, venomgfx, Blendify

Differential Revision: https://developer.blender.org/D2287