missing Q_DECLARE_METATYPE for QHostAddress

most QT objects such as QString and QByteArray have their metatypes declared allowing emitting of them across threads, but not QHostAddress. This appears to be an oversight.

simply adding the following to one of my cpp files fixes this

Q_DECLARE_METATYPE(QHostAddress);
class my_init { public: my_init()

};
static my_init _init;

eg use a signal like the follow and connect and emit across threads
signals:
void test(const QHostAddress& a);