Don't wrap std::vector into a QVariant when passing it to a Q_INVOKABLE (same for signals and slots if feasible)

Currently, any call of a Q_INVOKABLE taking a vector<int> or a QVector<int> or a QList<int> will wrap the container into a variant before doing the call. This seems highly undesirable for vector and quite unnecessary for the Qt containers. Teach the qv4qobjectwrapper CallArgument to pass such pointers to metacalls directly. That way a Q_INVOKABLE that takes a reference to such a container doesn't need to copy the container.