Cycles:

* Add alpha pass output, to use set Transparent option in Film panel.
* Add Holdout closure (OSL terminology), this is like the Sky option in the
  internal renderer, objects with this closure show the background / zero
  alpha.
* Add option to use Gaussian instead of Box pixel filter in the UI.
* Remove camera response curves for now, they don't really belong here in
  the pipeline, should be moved to compositor.

* Output full float values for rendering now, previously was only byte precision.
* Add a patch from Thomas to get a preview passes option, but still disabled
  because it isn't quite working right yet.
* CUDA: don't compile shader graph evaluation inline.
* Convert tabs to spaces in python files.

intern/cycles/render/CMakeLists.txt

@@ -15,7 +15,6 @@ set(sources
 	buffers.cpp
 	camera.cpp
 	film.cpp
-	film_response.cpp
 	filter.cpp
 	graph.cpp
 	image.cpp
@@ -39,7 +38,6 @@ set(headers
 	buffers.h
 	camera.h
 	film.h
-	film_response.h
 	filter.h
 	graph.h
 	image.h