first pass at new authn nav header
add icon to Change Plan button/link
whitespace only. 2 spaces, not tabs
fix some tab-vs-space bugs; localize all CSS to the #about page
tweek nav alignment just a little for vertical sanity
make authn site look slightly less terrible on a mobile device. NOTE that some things like managing/uploading will still not look/work well below 940px width
start on making home page, not-signed-in, responsive
fix featurebtn links on home page for mobile and otherwise
make all nav menu items inline-block to get consistent spacing
replace Zendesk sidebar tab with help link
tweek language, spacing
a kinder, gentler now-working icon, less apt to create anxiety
add meta viewport tag to tell mobile browsers to pay attention to media queries
move the full logo to footer when signed-in, use animated "up" block in upper left instead. shrink header nav height as a result.
Smaller logged in logo
bump up padding just a little, for that generous feel
tweek square logo a bit; reclaim 20px of header now that we don't need vert space
Merge branch 'authn-nav' into nov2014: #652