Added TypeConverter implementations for the Vector types and Element
Promoted Vector ordinate fields to Properties
Fixed Element.Get<T>() when result is null
Fixed Datamodel.Root setting Element ownership non-recursively
Made Datamodel.ImportElement thread-safe
Fixed destubbing in Datamodels without a StubRequest handler
Made AttributeTypeException constructor public
Updated DMXPad for Datamodel.NET changes (comparison mode still broken)
Various TreeGridView improvements
Added design data XAML
Added XAML note to readme