Removing the optional "Extension" suffix from Markup Extension name if present.
add unit tests for property setters
Made it possible to add resources to a ResourceDictionary through DesignItemProperty.CollectionElements.
Fixed bug; Only sets the inner text of an XML element if the element type defines a Content property.
add more unit tests
Its WPF standard to use parent type name as prefix before the dot when declaring a property as XAML element, and NOT the name of the type that declares the property.
Fixed so Resources are always first among child items.
XML-namespaces for controls outside the default XML-namespace is now declared in the document root.
As prefix for the XML-namespaces it primarily uses the value from XmlnsPrefixAttribute if it exists for the XML-namespace, otherwise a "ControlsX" name is generated, where X is the first free value.
adjusted unit test
Fixed so nodes in the property grid gets DesignItemProperty instances that really represents attached properties when an attached property is used.
When setting a property value as attribute, fixed so namespace prefix is only used for attached properties, and if no prefix is defined for a non-default namespace a new unique prefix is generated.
Removed Ignore attribute from SimpleLoadTests so the tests in the class will be executed.
Made some modifications to XamlParser so it aligns with the official XamlReader and the SimpleLoadTests will pass.
Removed Ignore attribute from WhitespaceTests so the tests in the class will be executed.
Made some modifications to XamlParser so it aligns with the official XamlReader and the WhitespaceTests will pass.
fix typo
If the ParentProperty is a collection the collection itself is the TargetObject (for example when adding Bindings to the MultiBinding.Bindings property).
Fixed bug where list with errors in the designer was only updated if the document failed to load completely.
Throws a XamlLoadException with an error message describing the error instead of a NullReferenceException in the case where the document failed to load.
Fixed missing namespace prefix on properties that is set as elements on types outside default XAML namespace.
Fixing this in CreatePropertyElement method also fixed another bug for AddChildNodeToProperty method that was fixed earlier in InsertNodeInCollection method with commit comment as follows:
"Its WPF standard to use parent type name as prefix before the dot when declaring a property as XAML element, and NOT the name of the type that declares the property."
Added default ReportErrors delegate that does nothing.

This is necessary after the fix in commit 295f62532f3be6cb42ed15128806afe08ca67a10.
Before that commit the ReportErrors was semi-optional; When loading was successful ReportErrors was never called (ReportErrors optional), but when document failed to be created a NullReferenceException was thrown because ReportErrors did not have a delegate.

See also commit 006558f253769244bfd0141b75d8ce1a6c52b62c, that throws a more friendly exception than NullReferenceException when document fails to load.
Fixed so its possible to use MultiBinding and PriorityBinding on a DesignItemProperty and that it writes as expected to XAML.
Its questionable if attached properties can be used in markup extensions. In either case, prefix should not be used for a normal property in markup extensions.