The method "QObject.signalname.disconnect(fund)" has issues.
Sometimes DOESN'T disconnect the Signal for real, even if it says it did.
This causes the "onShotCallbacks" (i.e. "onLoastStarted", "onLoadFinished"…)
fire again after they have been already consumed and disconnected.
The Qt MetaObject tries to invoke them, and causes a crash (as the actual pointer to the SLOT is actually gone).
Hence, I have made a workaround.
Callback handlers for those events are registered only
when the page is created: after that I add/remove
my own "OneShotCallbacks", using the actual
callback handlers as proxy to those.
Fixes multiple issues: #105, #113, #111, #109,