Added validate step, needs testing
Merge branch 'master' into 1880-check-duplicate-public-key
Adds validate :public_key_must_be_unique to AuthorizedKey which checks to see if the key
a) looks like a ssh-rsa key
b) that the key isn't already in the table
Use AJAX when adding a new authorized_key from the user home page.

On success, replace reminder box with a "Key added" message. On
failure, display the error message below the form.

refs #1880
Respond with an error status if save fails during create method.

refs #1880
Use render_error instead of custom error logic in update method.
Tweak error messages to render nicely as Rails "full messages".

"Public key does not appear to be ..."

refs #1880
Reduce boilerplate on error messages.

"The error message [API 422]" instead of "#<RuntimeError: API error
422: The error message>"

refs #1880
Accept DSA public keys ("ssh-dss"), not just RSA.

refs #1880
Add themes to .gitignore in apps/workbench
Merge branch '1880-check-duplicate-public-key'

closes #1880