Support for Pickling

The following PyQt5 classes may be pickled.

• QByteArray
• QColor
• QDate
• QDateTime
• QKeySequence
• QLine
• QLineF
• QPoint
• QPointF
• QPolygon
• QRect
• QRectF
• QSize
• QSizeF
• QTime

Also all named enums (PyQt5.QtCore.Qt.Key for example) may be pickled.