Adds support for MS SQL HierarchyId type to NHibernate 3

• GetAncestor - (HQL / Linq / QueryOver)
• GetDescendant - (HQL /Linq / QueryOver)
• GetLevel - (HQL / Linq / QueryOver)
• IsDescendantOf - (HQL / Linq / QueryOver)
• Parse - (HQL / Linq / QueryOver)
• GetReparentedValue - (HQL / Linq / QueryOver)
• ToString - (HQL / Linq / QueryOver)
• GetRoot - not implemented
• Read - not implemented
• Write - not implemented

For use all of this methods you must first register extensions in NH config:

using NHibernate.HierarchyId;
...
HierarchyIdExtensions.RegisterTypes(NHibernateConfigInstance)

For methods usage please see Tests project