Use semicolon after wxIMPLEMENT_*_CLASS* in wx's own implementations

wxIMPLEMENT_DYNAMIC/ABSTRACT_CLASS* is documented to be used with a
semicolon, though it is not mandatory.

Not touching headers yet, to avoid -pedantic warnings in user code.

See https://github.com/wxWidgets/wxWidgets/pull/2584

src/generic/richmsgdlgg.cpp

@@ -24,7 +24,7 @@
 #include "wx/statline.h"
 #include "wx/artprov.h"
 
-wxIMPLEMENT_CLASS(wxRichMessageDialog, wxDialog)
+wxIMPLEMENT_CLASS(wxRichMessageDialog, wxDialog);
 
 // ----------------------------------------------------------------------------
 // Events and handlers