signalInstanceEmit should use QtCore.QObject.emit(self, ...)

signalInstanceEmit should use QtCore.QObject.emit(self, "signal()", data) instead of MyClass.emit(self, "signal()", data), assuming MyClass inherits from QObject.

I bumped into this issue while creating a subclass from logging.Handler that I wanted to emit signals from, so I inherited from QObject too. But the problem is that logging.Handler needs you to implement emit(self, logRecord), so self.my_signal.emit(data) tries to use that implementation instead of QObject's one.

Here's a sample code for this error: https://gist.github.com/chiiph/5673107