Some defaulted ctor/dtors.

dw/image.hh

@@ -34,11 +34,9 @@ private:
          };
 
          std::list< std::unique_ptr< ShapeAndLink > > shapesAndLinks;
-         int defaultLink;
-      public:
-         ImageMap ();
-         ~ImageMap ();
+         int defaultLink= -1;
 
+      public:
          void draw (core::View *view, core::style::Style *style, int x, int y);
          void add (core::Shape *shape, int link);
          void setDefaultLink (int link) { defaultLink = link; };