Cycles / OSL: * Update the Oren Nayar shader to incorporate updates / fixes from r41968 and r44330. 
Cycles / OSL:
* Update the Oren Nayar shader to incorporate updates / fixes from r41968 and r44330. 

pyrochlore/cycles,pyrochlore/cycles,pyrochlore/cycles,tangent-opensource/coreBlackbird,tangent-opensource/coreBlackbird,tangent-opensource/coreBlackbird