Sanchez/tim 171 submission ui

This should complete TIM-171. Raises unit tests back to 95% coverage. Covers the bases for submission views, including past deadline, submission, submitted, and graded. In order to complete graded, I needed to get additional rubric / assessment information, and redesign the score calculation.  

You'll also notice some tweaking of the workbench xml to add an attribute that was introduce in the rubric work. 

I don't like my timestamp formatting; it there's a better idea around this, I'm all ears!

@wedaly @ormsbee @jrbl