Bug fixes and feature suggestions made by dev team. This review will gather number of small changes. It is not important to look at it now. Would be good to have them live soon after people are aware of the dashboard Strange values in dataset come from th

Summary:
0 is a bad name for missing sub group name since it's actually used as a real value

make fact that rows are clickable more obvious

hide graphs by default

Add thousand comma

reset hash on move back

Extract note about proficiency to separate template, include it in both places proficiency numbers are displayed

reset hash only on going to the table

fix concurrency issues and tabs triggering page reload with wrong data (through href=#element and _restoreUsingHash)

workaround for situation where there is no proficiency data for given exercise. Hopefully backbone defaults will solve the rest of the problem

Test Plan: Click around dashboard, nothing should be broken

Reviewers: chris, jace

Reviewed By: chris

Differential Revision: http://phabricator.khanacademy.org/D2410