Add category model for @muffinresearch

You can't use the builder for them (they're outside the page), but you can do `models('category').cast(foo)` to put categories into the model cache.
Fix paths to web fonts (cc @cvan)
Remove garbage from footer, update region link
Update quota management sniff to use storageInfo replacement
Fixed broken tests; better debug features

* Fix for Phantom user agent
+ Better logging (more tags, more logs)
* Improvements to navigation code paths, DRYer
- Removed noisy view routing logging
+ CasperJS now outputs stacktraces
Unit tests for new URL-related util functions
Added tests for caching and cache rewriting

+ Cache get/set/has/bust
+ Manual cache rewriting (a la reviews)
+ Implicit cache rewriting (a la pagination)
Update WebActivities for the current URL scheme
Run Travis against a few node versions
Remove superfluous `npm install` in .travis.yml
redesigned homepage and category browse pages - mobile & desktop (bug 860392)