public DisplayUserViewModel(Domain.Users.User user, IEncryptor encryptor)
        {
            UserId = user.Id;
            Email = user.Email;
            DisplayName = user.DisplayName;
            Roles = string.Join(", ", user.Roles);
            IsActive = user.IsActive;
            GravatarHash = encryptor.Md5Encrypt(Email).Trim().ToLower();

            AllRoles =
                (
                    from object role in Enum.GetValues(typeof (Domain.Users.Role))
                    select new RoleViewModel { RoleId = (int)role , RoleName = role.ToString(), IsSelected = user.IsInRole(role.ToString())}
                )
                .ToList();
        }