Turn roles off by default (see 760e9e9). Closes #11.

- Specify 'roles' package in package.js
Publish less data for blog index. Create/update excerpt upon save. Closes #7.
Add simple 'load more' pagination for blog posts. Closes #3.
'waitOn' causing problems with 'fast-render'?
Add Facebook OpenGraph & Twitter Card meta tags. Closes #12.
Replace EpicEditor with Ace Editor to get syntax highlighting. Closes #4.