Adding :presence_of_each validator

This is a courtesy validator and is included as an example of how to
do these things.
Adding validators as part of the load process
Adding Works::DatabaseStorage#state attribute
Sequestering data regardless of validity

Given that we are asking our users to upload files, and possibly
complex forms, this is the first step in saying "We have all of your
data, but would you consider continuing to edit your data?"
Adding switch on Create runner for response symbols

Given that we are allowing data to be persisted even if it is invalid
I want to issue a custom callback.
Appeasing the hound

At least to the best of my ability
Merge pull request #7 from jeremyf/persist-works-even-if-state-is-invalid

Persisting work even when data is not valid
Improving code coverage
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