Added ApplicationUserManager<TUser> because of missing functionality in the default UserManager<TUser> implementation.
Added RoleManager to the IUnitOfWork and UnitOfWork class.
Replaced the UserManager with the custom ApplicationUserManager.
Added RoleManager to the BaseApiController and replace the UserManager with the ApplicationUserManager.
Added UserController to the WebApi to handle user related operations.
Added User and UserRole classes to the Models project for transfer between the WebApi and a client.
Replaced private variables with protected ones.
Added WebApiUserHelper for user related tasks.
Added methods for getting a list of users, and adding a user to a role.
Added method to list all users.
Added method to add a user to a role.
SUBJECTED TO CHANGE!