ImagePaint Refactoring:

- ImagePaint now uses ImBuf directly, and the rect blending functions
  were moved into the imbuf module.
- The brush spacing, timing and sampling was abstracted into brush.c, for
  later reuse in other paint modes.

Float ImagePaint support.

Textured Brushes:
- Only the first texture channel is used now.
- Options for size and offset should be added, but need to find some space
  in the panel, or add a second one ..

source/blender/render/extern/include/RE_render_ext.h

@@ -44,8 +44,8 @@ struct Render;
 struct MTex;
 void    RE_zbufferall_radio(struct RadView *vw, struct RNode **rg_elem, int rg_totelem, struct Render *re);
 
-/* effect.c and editmesh_modes. */
-void	externtex(struct MTex *mtex, float *vec, float *tin, float *tr, float *tg, float *tb, float *ta);
+/* effect.c, editmesh_modes.c and brush.c, returns 1 if rgb, 0 otherwise */
+int	externtex(struct MTex *mtex, float *vec, float *tin, float *tr, float *tg, float *tb, float *ta);
 
 #endif /* RE_RENDER_EXT_H */