Raise a error when try to modify a read-only property.

Add get function as mandatory in QProperty constructor.

Reviewer: Marcelo Lira <marcelo.lira@openbossa.org>
          Luciano Wolf <luciano.wolf@openbossa.org>

libpyside/signalmanager.cpp

@@ -373,7 +373,6 @@ int SignalManager::qt_metacall(QObject* object, QMetaObject::Call call, int id,
             Py_XDECREF(pp_name);
             return id - metaObject->methodCount();
         }
-        printf("access to property: %s-%s\n", mp.name(), mp.typeName());
         typeResolver = Shiboken::TypeResolver::get(mp.typeName());
     }