"to/from" properties of some QtQuick animation classes are missing NOTIFY signals

The "to" and "from" properties of the following animation classes are writable but are missing the associated NOTIFY signal.

• QQuickColorAnimation
• QQuickNumberAnimation
• QQuickRotationAnimation
• QQuickVector3DAnimation

This leads to QML engine warning at runtime when these properties are being used in bindings, e.g.

import QtQuick 2.0

NumberAnimation {
    readonly property real diff: from - to
}