WL#2982: create asp.net 2.0 membership provider

Create a membershipprovider for asp.net 2.0

A membership provider provides a connection between the membership functionality
in ASP.Net 2.0 and a custom data source.  This is basically just an
implementation of a single class.

We won't need to create one from scratch. A user has contributed a membership 
and role provider that we are currently planning to ship with Connector/Net 5.1