Texturepaint now supports all the imagepaint brush settings, with the

exception of the clone tool.

One level undo for image- and texturepaint, only storing those tiles
that changed.

Test to improve texturepaint performance using glTexSubImage2D, only
enabled with 2^n sized textures and mipmapping off. Painting a 2048x2048
texture is then pretty smooth here, as long as the geometry is not too
complex.

source/blender/include/BDR_imagepaint.h

@@ -35,9 +35,10 @@
 
 void imagepaint_redraw_tool(void);
 void imagepaint_pick(short mousebutton);
+void imagepaint_paint(short mousebutton, short texturepaint);
 
-void imagepaint_paint(short mousebutton);
-void texturepaint_paint(short mousebutton);
+void imagepaint_undo();
+void free_imagepaint();
 
 #endif /*  BDR_IMAGEPAINT_H */