Sketcher: Bug fix: Undo/Redo implementation

================================================

Fixes a bug in master that the dependent 3D geometry would not update on Undo (in Auto update mode enabled).

Undo and redo signals are handled by ViewProvider in order to introduce an recompute or solve() of the sketchObject
as determined by the Auto Update Mode in order to update DoF and dependent geometry if necessary.

src/Mod/Sketcher/App/SketchObject.cpp

@@ -51,6 +51,8 @@
 #include <Base/Tools.h>
 #include <Base/Console.h>
 
+#include <App/Document.h>
+
 #include <Mod/Part/App/Geometry.h>
 
 #include "SketchObject.h"

src/Mod/Sketcher/App/SketchObject.h

@@ -227,7 +227,7 @@ protected:
     /// get called by the container when a property has changed
     virtual void onChanged(const App::Property* /*prop*/);
     virtual void onDocumentRestored();
-
+    
 private:
     std::vector<Part::Geometry *> ExternalGeo;