Region scrollbar fix!

Now scrollbars correctly hide and show, making space for the actual contents
in a region. It solves several old hacks, and puts view2d code a bit more
back in control as well. 

Implementation notes:

- The view2d mask feature is working again
- The #define V2D_SCROLL_HORIZONTAL_HIDE means: "turn on hiding".
- Code for UI_view2d_region_reinit() is enforcing better standard view settings

But... two hack/patches needed to be added:

- Region panel drawing: if after generating the button panels it appears
  a scroller hides or reveils, it calls all the generating code again.
  (a simple scale doesn't work due to rounding differences in layout code)

- View2d code that maps 'tot' and 'cur' rects: if this code detects that
  the mask changes, it calcs the map code again.

Also a bugfix (issue in 2.65)

- The left/bottom area split widget was drawing 1 pixel too large sometimes, 
  leaving bad trails on moving area dividers.

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/makesdna/DNA_view2d_types.h b/source/blender/makesdna/DNA_view2d_types.h
index 084496871bf..a7921be44d5 100644
--- a/source/blender/makesdna/DNA_view2d_types.h
+++ b/source/blender/makesdna/DNA_view2d_types.h
@@ -123,9 +123,9 @@ typedef struct View2D {
 	/* horizontal scrollbar */
 #define V2D_SCROLL_TOP 				(1<<2)
 #define V2D_SCROLL_BOTTOM 			(1<<3)
-	/* special hack for outliner hscroll - prevent hanging older versions of Blender */
-#define V2D_SCROLL_BOTTOM_O   		(1<<4)
-#define V2D_SCROLL_HORIZONTAL  		(V2D_SCROLL_TOP|V2D_SCROLL_BOTTOM|V2D_SCROLL_BOTTOM_O)
+
+/* UNUSED							(1<<4) */
+#define V2D_SCROLL_HORIZONTAL  		(V2D_SCROLL_TOP|V2D_SCROLL_BOTTOM)
 	/* scale markings - vertical */
 #define V2D_SCROLL_SCALE_VERTICAL	(1<<5)
 	/* scale markings - horizontal */