New users can sign up and are redirected to waiting area for admin approval

*New users can sign up
*New users cannot sign in until admin has enabled their account.
*Enabled users can sign in.

@mikeymurph77, @amZotti
How about `PendingUsersController` or `PendingAccountsController`?

Account is implied by "user" (or vice versa).
Approvals is implied by "pending".