converting value objects to/from QVariant

refs #81

src/blackmisc/avheading.h

@@ -72,6 +72,15 @@ namespace BlackMisc
              */
             CHeading(CAngle heading, ReferenceNorth north) : CAngle(heading), m_north(north) {}
 
+            /*!
+             * \brief Virtual method to return QVariant, used with DBUS QVariant lists
+             * \return
+             */
+            virtual QVariant toQVariant() const
+            {
+                return QVariant::fromValue(*this);
+            }
+
             /*!
              * \brief Equal operator ==
              * \param other