Use wx-prefixed macros throughout the repository.

Change {DECLARE,IMPLEMENT}_*CLASS and {DECLARE,BEGIN,END}_EVENT_TABLE
occurrences to use the wx-prefixed version of the macros.

demos/life/dialogs.h

@@ -34,7 +34,7 @@ public:
 
 private:
     // any class wishing to process wxWidgets events must use this macro
-    DECLARE_EVENT_TABLE()
+    wxDECLARE_EVENT_TABLE();
 
     int         m_value;
     wxListBox  *m_list;