Add yet another API endpoint
Change from using sprites or image-caching techniques to data URIs

- All active-state images become data URIs, embedded into CSS
- Add grunt task to generate the data URIs from image files
- No choice but to embed duplicate data URIs for border-image-source (prefixed and unprefixed)
- Note that iOS<=5.0 doesn't support -webkit-border-image-source longhand property
Clean up CSS
Much better message for outdated browsers
Give up if the browser doesn't support addEventListener
Change path to index.html
Uglify the JS files
Add tasks to bump appcache and deploy
Upgrade grunt-concurrent
Version date needs leading zeros
Bump appcache