Cycles: float texture support. Due to GPU limitations there are now 95 byte,

and 5 float image textures. For CPU render this limit will be lifted later
on with image cache support. Patch by Mike Farnsworth.

Also changed color space option in image/environment texture node, to show
options Color and Non-Color Data, instead of sRGB and Linear, this is more
descriptive, and it was not really correct to equate Non-Color Data with
Linear.

intern/cycles/render/nodes.h

@@ -64,6 +64,7 @@ public:
 
 	ImageManager *image_manager;
 	int slot;
+	bool is_float;
 	string filename;
 	ustring color_space;
 
@@ -78,6 +79,7 @@ public:
 
 	ImageManager *image_manager;
 	int slot;
+	bool is_float;
 	string filename;
 	ustring color_space;