Increased epsilon to 1e-4, earlier 1e-5 was causing clips in simple mirror sphere scenario
fixed: Specular BRDF was missing cosine term compensation
added FresnelConductor
added test_tir.lisc
Metal and Mirror materials
detect and count NaNs and negatives in output
Streamlined surface integerator structure.
fixed: ThinsLens cameras y-axis was inverted
RGBE output was mirrored vertically
pinhole camera output was mirrored horizontally
user definable block size and ability to calculate a single pixel