Use QCoreApplication instead of QApplication

For non-GUI application QCoreApplication should be used. This allows
application to start when no X server available or any other window system.

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <norluk@luxoft.com>
Change-Id: I605211dd5d651f09a3a59cb3516ad705b697c46c