Sammy.js using Bower + new design + Sammy upgrade

I wanted to try converting the Sammy.js app to use Bower (#475), mostly because it was a library I hadn't worked with before. After I mentally made the commitment, I realized Sammy.js itself was out of date, as well as the design and functionality of the app. So, as a learning experiment, and hopefully a helpful contribution, I upgraded and updated. Let me know if I missed anything, or can improve!