Orange: and now for the real exr fun: float buffer support in Image window!

Image as loaded in Blender (from openexr.com):
http://www.blender.org/bf/exrcurve1.jpg

Image with different white point:
http://www.blender.org/bf/exrcurve2.jpg

Image with white and black point and a curve:
http://www.blender.org/bf/exrcurve3.jpg

Use SHIFT+click to set the black point, and CTRL+click for white point.
The buttons in the panel work too, of course.

The curves work after the black/white range was corrected, so you can
stick to curves with a normal 0-1 range.
There's also now a general color curve, marked with 'C' button.

Note; this currently only maps the float colors to a visible 8 bits per
channel rect. You can save it, but when the blender file loads the curve
or mapping is not executed until you click in the curves... have to look
at that still.
Speed for this is also quite unoptimized... still WIP, but fun!

source/blender/include/BIF_editsima.h

@@ -67,5 +67,7 @@ void weld_align_tface_uv(char tool);
 void be_square_tface_uv(struct Mesh *me);
 void select_pinned_tface_uv(void);
 
+void sima_sample_color(void);
+
 #define UV_SELECT_ALL		1
 #define UV_SELECT_PINNED	2