SnLinq support for the Client.NET

[kavics]

Create a LINQ provider for the Client.NET. Example codes:

1. Get a user by part of the login name

   var user = repository.Content
   .OfType<User>()
   .Where(u => u.LoginName.Contains("john"))
   .FirstOrDefault();

2. Get the latest 5 articles

   var articles = repository.Content
   .OfType<Article>()
   .Where(a=> a.InTree("/Root/Content/Articles"))
   .OrderByDescending(a => a.CreationDate)
   .Take(5)
   .ToArray();

3. The new projection and auto expansion

   var users = repository.Content
   .EnableAutofilters()
   .CountOnly()
   .DisableLifespan()
   .Where(c => c.Id < 100 && c is User)
   .OfType<User>()
   .Select(u => Content.Create<User>(
       u.Id,
       u.Domain,
       u.LoginName,
       u.Email,
       u.Manager.Id,
       u.Manager.Type,
       u.Manager.Path,
       u.Manager.FullName,
       u.CreatedBy.Id,
       u.CreatedBy.Type,
       u.CreatedBy.Path,
       u.CreatedBy.FullName,
       u.ModifiedBy))
   .ToArray();