Box plot for student dashboard.

Tiny, needs styling. But it's ~*~there!!!!~*~
Style for box plot.
Same controller method for box and bars.
Move box plot to user_dashboard.js.
Clean up.

Download Sparklines.
Refactor controller.
Simplify Haml.
Edit query to get released grades.
Closes #251
Merge branch 'master' of github.com:bellotastudios/gradecraft-development
Box plot for student dashboard.

Tiny, needs styling. But it's ~*~there!!!!~*~
Style for box plot.
Same controller method for box and bars.
Move box plot to user_dashboard.js.
Clean up.

Download Sparklines.
Refactor controller.
Simplify Haml.
Edit query to get released grades.
Rebased on master
Merge pull request #223 from bellotastudios/whisker

[Reviewed] Box and whisker plot for student dashboard.