QmlDesigner.Property: add backendValue to ColorEditor

We use a timer for now to keep ui responsive.

Change-Id: I0385f2fd49c65e591869d0daff9260f0b08d48fd
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner.PropertyEditor: fix color editing in RectangleSpecifics

Change-Id: I9c504f708e0d52fce2cb7c6fa3fe1b021c257435
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner.PropertyEditor: fix color editing in TextEditSpecifics

Change-Id: I90c9743d6ec19b557721c45913da480f30b34e16
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner.PropertyEditor: fix color editing in TextInputSpecifics

Change-Id: I2e966f20df778f01ae1ea854f58ace37f8e767a9
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner.PropertyEditor: fix color editing in TextSpecifics

Change-Id: I62b34d2b1043ac403c0965c0ce1cf96ef4182d3e
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner.PropertyEditor: disabling slider in SliderSpinBox

This just looks broken atm.

Change-Id: Id7064fa92e3bbfeac693cf500ec268090e641ea4
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>