QmlDesigner.PropertyEditor: Remove print from .qml

Change-Id: Ifce18301b05e4c05e490ce1b46a2b8e3beab9d40
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner.PropertyEditor: Fix check in ColorEditor

Checking for visibilty is a bad idea. Instead we check if
the item actually has a gradient.

Change-Id: Ib14de1fbc570c28332e7e240052b4820c5b1483c
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>