Corrected Heading Usage
Hiding Non-Actionable Icons from Screen Readers
Hiding Graphs from Screen Readers
Differentiating Download CSV Text for Screen Readers
Removed Extraneous HTML Surrounding Course ID
Updated Page Structure and Added ARIA Labels
Identifying Active Navigation Items for Screen Readers
Added Bootstrap Accessibility Plugin

This plugin will make tooltips and dropdowns accessible.
Merge pull request #104 from edx/a11y-fixes

a11y fixes