+- Have wxDirCtrl as alias for wxGenericDirCtrl.
+- Allow instant reaction to left-up in a wxGrid cell
+ (extend editor API) to work around bad checkbox
+ behaviour (click, click, click, click away...) and
+ reduce checkbox size on non-Windows platforms.
+- Add wxNotebook::HitTest for non-Windows platforms.
+- Implement rebar for all platforms. This will help us
+ get closer to native look and feel, e.g. the gradient
+ shadow on XP toolbars.