update SAM_ITEMGRADING_T multiplies as user progresses through long assessment

Functional test: Check that student answers continue to be saved while progressing through a test: create a 10 question test (one question per page), start taking it as a student, answer the first 5 questions then close browser without submitting. Open browser, login again as student, restart test, check that answers were saved. Performance test: Check that response time does not decrease linearly when progressing through a large test. Enable mysql query logging on db and count the number of UPDATE queries while progressing through a test. Load test: It would be something along these lines using selenium or other scripting tool in order to simulate large numbers of students taking a test at the same time (300-400). Google Testing Sheet