move Freeze() and Thaw() to wxWindowBase to ensure that they behave consistently (i.e. recursively, as described in the docs) in all ports; removed different duplications of freeze count from derived classes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51018 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/x11/textctrl.h

@@ -205,9 +205,6 @@ public:
 
     void SetModified() { m_modified = true; }
 
-    virtual void Freeze();
-    virtual void Thaw();
-
     // textctrl specific scrolling
     virtual bool ScrollLines(int lines);
     virtual bool ScrollPages(int pages);