Make FeaturePython Python binding a template class to avoid code duplication

src/App/FeaturePython.h

@@ -31,13 +31,11 @@
 #include <App/DynamicProperty.h>
 #include <App/PropertyPythonObject.h>
 #include <App/PropertyGeo.h>
-#include <App/FeaturePythonPy.h>
 
 namespace App
 {
 
 class Property;
-class FeaturePythonPy;
 
 // Helper class to hide implementation details
 class AppExport FeaturePythonImp
@@ -48,6 +46,7 @@ public:
 
     DocumentObjectExecReturn *execute();
     void onChanged(const Property* prop);
+    PyObject *getPyObject(void);
 
 private:
     App::DocumentObject* object;
@@ -188,7 +187,7 @@ public:
     PyObject *getPyObject(void) {
         if (FeatureT::PythonObject.is(Py::_None())) {
             // ref counter is set to 1
-            FeatureT::PythonObject = Py::Object(new FeaturePythonPy(this),true);
+            FeatureT::PythonObject = Py::Object(imp->getPyObject(),true);
         }
         return Py::new_reference_to(FeatureT::PythonObject);
     }
@@ -199,8 +198,6 @@ public:
             FeatureT::PythonObject = Py::None();
     }
 
-    friend class FeaturePythonPy;
-
 protected:
     virtual void onChanged(const Property* prop) {
         imp->onChanged(prop);