disable SSE-specific assertions when SSE is disabled.
adjust the epsilon value in a unit test in an attempt to make it pass on 32-bit Linux.
More OSL closures work.
Merge pull request #329 from est77/OSL_work

More OSL closures work.
Small formatting fixes to stdosl.h
Translucency should be a color, not a scalar
Copy and cleanup bsdf showdown test.
Split colors and multipliers in Ashikhmin brdf.
Small formatting fix
OSL Ashikhmin BRDF changes. Added Ashikhmin to closures test scene.
Merge pull request #330 from est77/OSL_work

OSL Ashikhmin BRDF work, added (WIP) sample OSL closures scenes.
Merge https://github.com/appleseedhq/appleseed
Translucency should be a color, not a scalar