Bib Record Details error message

Hi,

The JavaScript that was controlling the BibRecord screen makes the form show up green when successful, and red when unsuccessful.  It also disables the button when there is an error.  However, the AJAX service always responds with a HTTP 200!  This PR changes the method to set the response code to a 400 when returning an error.

Also display a better error message than "record not found", with a little error icon like we do elsewhere, etc.

Huw