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.

utils/hhp2cached/hhp2cached.cpp

@@ -26,7 +26,7 @@ public:
     virtual bool OnInit();
 };
 
-IMPLEMENT_APP(MyApp);
+wxIMPLEMENT_APP(MyApp);
 
 bool MyApp::OnInit()
 {