Consolidate infrequent navigation into dropdown via username
Button nav UI
Convert nav to tabs
Tweak nav, squish sidebar down below navbar
Login & signup buttons colorful and bigger
Move points into dropdown
Inset border and box shadow for depth on sidebar
Expand outermost topic entry to 1.5x width and include it's description.
Merge branch 'develop' of github.com:learningequality/ka-lite into nav-polish
Restyling the sidebar entries to not wrap titles.
Style tweak and make truncate helper more robust
Style related content boxes
Merge branch 'develop' of github.com:learningequality/ka-lite into nav-polish

Conflicts:
	kalite/distributed/hbtemplates/topics/sidebar-entry.handlebars
	kalite/distributed/static/css/distributed/sidebar.css
	kalite/distributed/templates/distributed/base.html
	kalite/distributed/templates/distributed/topic.html
Update browser_is_logged_in to match new develop front-end code
Merge pull request #2522 from dylanjbarth/nav-polish

Some front end prettifications and tweaks