Andy implements IUpdatable for LINQ to SQL

The post went up recently - find it over at https://blogs.msdn.com/aconrad/archive/2008/11/05/iupdateable-for-linq-to-sql.aspx.

One of the things that I love about the interface is that, while it has a fair number of methods to implement (we wanted to keep it very close to what the wire payloads tell us), the implementation of each method is quite straightforward.

Nitpicking: personally, I'd throw a NotImplementedException from ClearChanges, but that's probably because I spend too much time crafting my own requests over telnet.