Fixed a potential live-lock situation: Signals from the QThread can get lost, before...

Fixed a potential live-lock situation: Signals from the QThread can get lost, before we reach the QEventLoop->exec(), even if the required connections already exists. It seems that QApplication::processEvents() will discard signals for our QEventLoop, if that QEventLoop is not running yet! Without the QApplication::processEvents(), those signals would simply be enqueued until we call QEventLoop->exec(). In reality this bug was never triggered under normal circumstances, but it seems on some systems it can take longer to perform the "fade in" than to finish the initialization thread. In that situation the bug *was* triggered and caused the live-lock...