Testing charting.
Sparklines for the admin dashboard.
Fix errors with sparkline.
Fix redirect error.
Fix routing, move query into User model.

Fixed the routing. The query to obtain the chart data will now return
some data based on the user id provided. However, I don't believe the
current query is correct because it does not take the current course
into account. I'll add that in a subsequent commit.

However, now would be a good time for someone to generate a graph using
the returned JSON.

See #197.
See #145.
Display bar charts on instructor dashboard.

See #197.

Sparklines does not support stacked bar charts. Waiting for further word on that.
Only added charts to the top ten view for now.
Merge branch `master` into `visuals`.

Conflicts:
	app/assets/javascripts/application.js
	app/controllers/users_controller.rb
	app/views/info/_students_table.haml
	vendor/assets/javascripts/jquery.sparkline.min.js
Merge branch `visuals` into `master`.