Added wxBORDER_THEME, wxWindow::GetDefaultBorderForControl(), wxWindow::CanApplyThemeBorder().

wxTextCtrl and wxSearchCtrl now get the correct border on wxMSW, and the wxRichTextCtrl sample
also now demonstrates correct borders.



git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@47927 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/textctrl.h

@@ -170,6 +170,9 @@ public:
 
     virtual bool AcceptsFocus() const;
 
+    // returns true if the platform should explicitly apply a theme border
+    virtual bool CanApplyThemeBorder() const;
+
     // callbacks
     void OnDropFiles(wxDropFilesEvent& event);
     void OnChar(wxKeyEvent& event); // Process 'enter' if required