[PyQt] ANN: PyQt v5.9 and SIP v4.19.3 Released

PyQt v5.9 and SIP v4.19.3 have been released. The highlight is support for Qt v5.9.0 and v5.9.1. There are also new releases on PyQt3D, PyQtChart, PyQtDataVisualization and PyQtPurchasing. The PyQt documentation has also received some attention. At the moment the main visible changes are the improved indexing and the inclusion of the PyQt3D, PyQtChart etc. classes. However things are now in place to make it much easier to make much more significant improvements in the future. Phil