Draft: modernize C++11

* use nullptr

src/Mod/Draft/App/AppDraftUtils.cpp

@@ -43,7 +43,7 @@ PyMOD_INIT_FUNC(DraftUtils)
     }
     catch(const Base::Exception& e) {
         PyErr_SetString(PyExc_ImportError, e.what());
-        PyMOD_Return(0);
+        PyMOD_Return(nullptr);
     }
     PyObject* mod = DraftUtils::initModule();
     Base::Console().Log("Loading DraftUtils module... done\n");

src/Mod/Draft/App/AppDraftUtilsPy.cpp

@@ -58,7 +58,7 @@ private:
     {
         Base::Console().Warning("DraftUtils.readDXF is deprecated. Use Import.readDxf instead.\n");
         char* Name;
-        const char* DocName=0;
+        const char* DocName=nullptr;
         bool IgnoreErrors=true;
         if (!PyArg_ParseTuple(args.ptr(), "et|sb","utf-8",&Name,&DocName,&IgnoreErrors))
             throw Py::Exception();