QSignalTransition does not increment the receivers on QObject

QSignalTransition does not increment the receivers() on QObject.

D-Bus seems to use receivers() as an optimization, so that if I do something like

s1->addTransition(someDBusObject, SIGNAL(someSignal(), s2);

the signal is not emmitted, because D-Bus considers nothing to be connected to it.

I attached unit tests but didn't attempt to fix it.