Added Billy's Billing to See Who's Using Ember.js
Merge pull request #322 from sebastianseilund/master

Added Billy's Billing to See Who's Using Ember.js
API: do not UPCASE code in headers
upgrade middleman + middleman blog
add basic tagging support to blog
add sidebar to blog tag page
more consistent summaries on tag pages
remove blog seperator (our templates got this covered)
request.path changed slightly, and we where depending on it
 API: tabs need .active/:hover styling
resurrect the api filters
 hide tabs if no content is present
remove github link

It felt out of place in the side bar, and looked bad when it overflowed
We should find a way to make the "defined in" look like its actually
linked to GH
Revert "remove github link"

This reverts commit 8d1608f042a70fa4018558ba1213722ff486c4bc.
remove github link 4 realz
api sidebar links learn to give nice interaction feedback
active/hover
restore left padding on api sidebar links (i need a bigger display at
home)
improve tab border-radius
api method anchorability.
fix anchors + filters