* Sun, area and point lights with size now supported
* Cast shadow option to disable shadow casting for lamps
* Emission strength of materials tweaked such that setting strength to 1.0
basically makes the material "shadeless" in that the value of the color
input will be the resulting color in the image.
* Fix missing update when editing objects with emission materials.
* Fix preview pass rendering set to 1 not showing full resolution.
* Fix CUDA runtime compiling failing due to missing cache directory.
* Use settings from first render layer for visibility and material override.
And a bunch of incomplete and still disabled code mostly related to closure
sampling.