Add a 'Stamp' widget.

Place one or multiple stamps on scanned pages in defined locations.

A stamp is understood here as
 - a transparent text in a transparent frame with no borders
 - an opaque text on an opaque background with no borders.

Stamp parameters:
 - text
 - font
 - foreground colour
 - background colour
 - angle of rotation
 - transparency.

Locations:
 - centre
 - cardinal directions
 - inter-cardinal directions.

XS7.h

@@ -17,6 +17,7 @@
 
 class XS7 : public S7
 {
+  DECLARE_DYNAMIC_CLASS( XS7 )
 public:
   XS7(wxWindow* parent, wxWindowID id = SYMBOL_S7_IDNAME, const wxString& caption = SYMBOL_S7_TITLE,
       const wxPoint& pos = SYMBOL_S7_POSITION, const wxSize& size = SYMBOL_S7_SIZE, long style = SYMBOL_S7_STYLE );