Make wxDECLARE_CLASS synonym of wxDECLARE_ABSTRACT_CLASS.

Previously wxDECLARE_CLASS was a synonym for wxDECLARE_DYNAMIC_CLASS which was
inconsistent with its documentation and wxIMPLEMENT_CLASS that was the same as
wxIMPLEMENT_ABSTRACT_CLASS.

Resolve this in the most backwards compatible and also arguably logical way.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67879 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/rtti.h

@@ -144,7 +144,7 @@ WXDLLIMPEXP_BASE wxObject *wxCreateDynamicObject(const wxString& name);
     static wxObject* wxCreateObject()
 
 #define wxDECLARE_CLASS(name)                                                 \
-    wxDECLARE_DYNAMIC_CLASS(name)
+    wxDECLARE_ABSTRACT_CLASS(name)
 
 
 // common part of the macros below