QtQuick.Dialogs.ColorDialog: set current color in the QColorDialog
QtQuick.Dialogs.ColorDialog: set current color in the QColorDialog

It was a missing feature to set the current color programmatically,
either before or after showing the dialog.

Task-number: QTBUG-32621
Change-Id: I62a811f7c36eaab5356c5924bf3447deca55ada3
Reviewed-by: Liang Qi <0f3d3d9587f4f01263b2640b7eef7a92a160ec94@digia.com>

matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d