make IsEnabled() return false even if the window parent, and not the window itself, is disabled and added IsThisEnabled() implementing the old IsEnabled() behaviour; also significantly simplify the window state management code in all ports by factoring out the common parts in wxWindowBase

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45031 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/textctrl.h

@@ -155,7 +155,7 @@ public:
     // wxGTK-specific: called recursively by Enable,
     // to give widgets an oppprtunity to correct their colours after they
     // have been changed by Enable
-    virtual void OnParentEnable( bool enable ) ;
+    virtual void OnEnabled( bool enable ) ;
 
     // tell the control to ignore next text changed signal
     void IgnoreNextTextUpdate(int n = 1) { m_countUpdatesToIgnore = n; }