Implement new active link highlighting in navagation bar
Add context processor used for retrievent current page url
Fix page's footer
Remove the old ModuleViewMixin used to hightlight active link
Update <th>'s style
Migrate challenge page to bootstrap
Migrate special challenge to bootstrap
Migrate special quest page to bootstrap
Squeeze left navigation menu's height to fit page without scrolling
Migrate pagination to bootstrap
Migrate reports page to bootstrap
Some more bootstrap changes