Stanford-Online/class2go — pull request #1255 by jbau (2012-11-08 03:35:51+00:00)
Title: #1253 exam record bad json handling

@sefk

Do error handling in several ways:
* Check at input time (submission collection endpoint)
* calls to postdata = request.POST['json_data'] and json.loads(postdata) will fail and return error to user (displayed in popup) if the POST contains bad JSON
* In student feedback page, if the JSON submission is malformed, inform the student
* In CSV file of all student submissions, list at the top the username of students whose submissions we were not able to parse, meaning they were bad JSON.