Cycles: merge of changes from tomato branch.

Regular rendering now works tiled, and supports save buffers to save memory
during render and cache render results.

Brick texture node by Thomas.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Brick_Texture

Image texture Blended Box Mapping.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Image_Texture
http://mango.blender.org/production/blended_box/

Various bug fixes by Sergey and Campbell.
* Fix for reading freed memory in some node setups.
* Fix incorrect memory read when synchronizing mesh motion.
* Fix crash appearing when direct light usage is different on different layers.
* Fix for vector pass gives wrong result in some circumstances.
* Fix for wrong resolution used for rendering Render Layer node.
* Option to cancel rendering when doing initial synchronization.
* No more texture limit when using CPU render.
* Many fixes for new tiled rendering.

source/blender/gpu/shaders/gpu_shader_material.glsl

@@ -2114,6 +2114,12 @@ void node_tex_checker(vec3 co, vec4 color1, vec4 color2, float scale, out vec4 c
 	fac = 1.0;
 }
 
+void node_tex_brick(vec3 co, vec4 color1, vec4 color2, vec4 mortar, float scale, float mortar_size, float bias, float brick_width, float row_height, out vec4 color, out float fac)
+{
+	color = vec4(1.0);
+	fac = 1.0;
+}
+
 void node_tex_clouds(vec3 co, float size, out vec4 color, out float fac)
 {
 	color = vec4(1.0);