[gtk+] (17 commits) ...Merge branch 'transparent-windows'

[Alexander Larsson <alexl src gnome org>]

Summary of changes:

  45df163... gdk: Remove now unused region tags completely (*)
  7fd225c... gdk: Expose bottommost windows first (*)
  9613e6a... testwindows: Test transparent backgrounds (*)
  30ad4e6... testwindows: Add a button to cause a repaint (*)
  f51482e... gdk: Track wether windows have alpha in the background (*)
  46d5b89... gdk: Track the layered area (*)
  0f6784a... gdk: Make sure we don't copy to/from layered regions when m (*)
  f0c8c4a... gdk: Fix repaint of layered region during raise (*)
  8e28f53... gdk: Fix repaint of layered region during scroll (*)
  7a263c6... gdk: Fix repaint of layered region during move_region (*)
  f00cfe1... Handle has_alpha_background for parent-relative backgrounds (*)
  68843a3... gdk: Remove unused _gdk_window_calculate_full_clip_region (*)
  76ea768... gdk: Fix alpha window background paintings on non-implicit  (*)
  65ef158... gdk: gdk_window_move_region (*)
  4597f1e... gdk: gdk_window_get_update_area don't remove alpha covered  (*)
  93c086e... Make window handle transparent (*)
  c47ef89... Merge branch 'transparent-windows'

(*) This commit already existed in another branch; no separate mail sent