Adding dragonfly gem

> A Ruby gem for on-the-fly processing - suitable for image uploading
> in Rails, Sinatra and much more!

See https://github.com/markevans/dragonfly for more details
Adding ValuePresenter#label

Because I'm going to want to deal with this in a special way.
Adding ENV['DEBUG'] option for template rendering

Given the complexity of the view rendering, it is helpful to have a
view into the problems encountered.
Adding attachment rendering options for new/show

Working on handling file uploads via attachments.
Adding multipart encoding to forms.

I am uncertain why the forms don't default to `multipart: true`
Adding DateParser spec
Adding attachment parsers
Rearranging service methods

Removing custom builder functions for storage
Adding stubbed spec for persisting files
Preparing the way for file attachment
Incorporating Dragonfly::Model into Attachments
Merge branch 'working-on-file-uploads'

* working-on-file-uploads:
  Incorporating Dragonfly::Model into Attachments
  Preparing the way for file attachment
  Adding stubbed spec for persisting files
  Rearranging service methods
  Adding attachment parsers
  Adding DateParser spec
  Adding multipart encoding to forms.
  Adding attachment rendering options for new/show
  Adding ENV['DEBUG'] option for template rendering
  Adding ValuePresenter#label
  Adding dragonfly gem