Present a generated form for the resident showing preferred fields

Now there's a common form to fill, based on selected PDFs.
Create a global Dragoman object

This seems more efficient and cleaner than re-creating a Dragoman object every
time a resident wants to know something about a set of field names.

In the context of this app, Dragoman seems like a good candidate for a
singleton object, since all of the translation rules sent to Dragoman#learn
never change.

This also gives us a nicer place to store all of the translation rules, in
config/initializers/dragoman.rb.
Clean up logger calls and unnecessary Dragoman nil provider