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, 2 insertions, 2 deletions

diff --git a/source/blender/blenloader/intern/versioning_250.c b/source/blender/blenloader/intern/versioning_250.c
index 1521739258e..f4d841fd22a 100644
--- a/source/blender/blenloader/intern/versioning_250.c
+++ b/source/blender/blenloader/intern/versioning_250.c
@@ -292,7 +292,7 @@ static void area_add_window_regions(ScrArea *sa, SpaceLink *sl, ListBase *lb)
 					memcpy(&ar->v2d, &soops->v2d, sizeof(View2D));
 
 					ar->v2d.scroll &= ~V2D_SCROLL_LEFT;
-					ar->v2d.scroll |= (V2D_SCROLL_RIGHT|V2D_SCROLL_BOTTOM_O);
+					ar->v2d.scroll |= (V2D_SCROLL_RIGHT|V2D_SCROLL_BOTTOM);
 					ar->v2d.align = (V2D_ALIGN_NO_NEG_X|V2D_ALIGN_NO_POS_Y);
 					ar->v2d.keepzoom |= (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_KEEPASPECT);
 					ar->v2d.keeptot = V2D_KEEPTOT_STRICT;
@@ -415,7 +415,7 @@ static void area_add_window_regions(ScrArea *sa, SpaceLink *sl, ListBase *lb)
 					ar->v2d.tot.ymax = ar->winy;
 					ar->v2d.cur = ar->v2d.tot;
 					ar->regiontype = RGN_TYPE_WINDOW;
-					ar->v2d.scroll = (V2D_SCROLL_RIGHT|V2D_SCROLL_BOTTOM_O);
+					ar->v2d.scroll = (V2D_SCROLL_RIGHT|V2D_SCROLL_BOTTOM);
 					ar->v2d.align = (V2D_ALIGN_NO_NEG_X|V2D_ALIGN_NO_POS_Y);
 					ar->v2d.keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_LIMITZOOM|V2D_KEEPASPECT);
 					break;