removing landing page user creation

[brianashpugh]

for now, it is possible for users to 'sign up' on the landing page, after which they are placed in a 'temp' house. if the final flow for adding users will consist of only mass user adding by managers and admins, then this feature can be removed to avoid confusion.

for purposes of adding single new users (such as those wanting to test the site), it is easy enough for one to sign in as a manager and create a single new user account.