QmlDesigner.PropertyEditor: Ading missing QtQuick 2 only properties

Those properties are QtQuick 2 only and were missing in the
property editor.

Change-Id: Ie58a4eac86b945bdde24d32fc373396268bb593e
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
QmlDesigner.MetaInfo: Adding convincience function for testing

Change-Id: Ic9faddd21fdf80357b1360951a1cc054546866e9
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>