1. removed wxObject::CopyObject() and Clone() - some objects just can't be

copied
2. made wxEvent::Clone() pure virtual and added missing Clone()s to the
   other event classes which this changes has helped to discover


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@12566 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/event.h

@@ -359,8 +359,10 @@ public:
     // exists only for optimization purposes.
     bool IsCommandEvent() const { return m_isCommandEvent; }
 
-    // specialized clone function since it is done a lot
-    virtual wxEvent *Clone() const { return new wxEvent(*this); }
+    // this function is used to create a copy of the event polymorphically and
+    // all derived classes must implement it because otherwise wxPostEvent()
+    // for them wouldn't work (it needs to do a copy of the event)
+    virtual wxEvent *Clone() const = 0;
 
 public:
     wxObject*         m_eventObject;