Finishing encrypted data bag UX

Spec: https://gist.github.com/sersut/94c8daad5c11369bd2e8

The original PR is https://github.com/opscode/chef/pull/1902.  When I tried to check it out, it gave it to me in a detached head state.  Maybe the branch was already deleted?

I'm recreating here.  Commits up to '[Fixing bad method definition](https://github.com/opscode/chef/commit/1cf440ed243a6900a01070ef04b903757c350f6e)' were covered in the previous review.