* generate_run creates a RunID for the supplied questionnaire id,
associating it with a Subject with givenname "Anonymous" and
surname "User" (will create the Subject if it doesn't exist).
* Fixes issue #3 in github
* Thanks to Ross Poulton (http://www.rossp.org/)
* stricter permission check on export_csv (questionnaire.export)
* stricter permission check on send_email (questionnaire.management)
* small bugfix for case when runcode is empty