[Development] invokeMethod() with function pointers

[Gunnar Roth]

> 
> I respect the fact that you rejected Qt::BlockingAutoConnection in 2014 because of its potential danger, but I'm not sure that it's better to let people use the "QThread::currentThread() == this" pattern without being warned rather than implementing Qt::BlockingAutoConnection, with a detailed warning in the doc.
> 
> Moreover, I don't understand whi BlockingAutoConnection would be more dangerous (if it were to be added) than BlockingQueuedConnection is currently already dangerous.

I also don’t understand why adding  "QThread::currentThread() == this“ should make the method more dangerous, actually it makes it a bit more safe for the same thread case, the potential deadlock problem remains with or without.

Regards,
Gunnar Roth