Added unit test for using SolidColorBrush as a resource. This also tests that the inner text of an XML element is only set if the element type defines a Content property.
Fixed ignored SetPropertyTests; Must set the property value on the DesignItem representing the object, otherwise the value will not get written to XAML.
Added namespace tests to test XML-namespaces that is added automatically in the document root when controls or types outside the default XML-namespace is used.
Added tests for testing that property values are written correctly as attribute in XAML; namespace prefix should only be used for attached properties, and prefix should be generated and added if not already present.
Added tests for testing property values set as element, with proper prefix for types outside default XML-namespace.
Merge remote-tracking branch 'origin/WpfDesignerUnitTests'