2013-06-04 MySystem built from c5645ab.

* Add docs ( http://concord-consortium.github.io/mysystem_sc/help.html )
* Add 'free' feedback -feedback that doesn't count against submit counts
* API: Add post message api for post-hock grading tool.
* FIX: Easier and persistent authoring of initial diagram.
* FIX: Author can preview curriculum relative images  (assets/foo.png)