Problem:
When an SRM Request has files that had errors during transfer and someone attempts to download those files with errors, the gateway returns an internal server error message instead of something more useful.

Acceptance Criteria:
When attempting to download an expired file we need to return a 410 (gone)
Check if request is expired and if not, if file is expired. (maybe?)
Also check if file exits and if not, raise error and show error page.
In error (JSP) page, include a message explaining the problem and how to fix the problem (giving a link to the original request so that it can be resubmitted).