Move person form components to a partial
Improve speed of rake db:seed

Generating PDF form field lists was taking over a minute.  With transactions, it
now takes just a few seconds.
Use single table inheritance to distinguish Person relations

HouseholdMember, Identity, and Landlord are new classes that inherit from
Person.  We can now fetch people related to the applicant with Active Record
Association helpers, like:

applicant.identity
applicant.landlords
applicant.household_members
SSNs are 9 digits, not 8
Make existing houshold members and landlords editable
Remove some <p> tags from the main form

I don't know why those are there.
Make the <hr> tags proper empty elements
Household members and landlords can be removed
Rename partial person_form to person_fields

Because it's a collection of fields, not a whole form.  Following the style of
http://railscasts.com/episodes/196-nested-model-form-part-1
Allow adding household members and landlords
Identity residence is editable
Distinguish Residence from MailAddress with single table inheritance

This probably won't be sustainable, since people can't share addresses, but it should
at least be quick to get something working.
Use a random state for 742 Evergreen Terrace
Provide random addresses to seed people
mail -> mail_address
Update test fixtures for new address scheme
Remove the auto-generated browsing test
Make guard work with minitest
Fill household members and landlords in PDFs
Remove preferred_phone from Person