This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
* Add user_home configuration option
* Use the new user_home preference to actually show the right home page
* Fix trailing whitespace
* Update user_option_serializer.rb
* Fix JavaScript default homepage tests
* Use an object instead of a giant switch
* Remove trailing whitespace
* Make the default `user_home` set to `null` instead of `0`
* Rename user_home to homepage_id
Adds a "Step 0" to the wizard if the site has no admin accounts where
the user is prompted to finish setting up their admin account from the
list of acceptable email addresses.
Once confirmed, the wizard begins.
