serenade updated to use bower.

Just switched this one over. Serenade wasn't in bower, so I registered it. Then, I realized that was a mistake, since there aren't any compiled, distributable files in the Serenade repo. Just src files and build instructions.

I then found it as an NPM package, so I created a package.json with that as a devDependency, as well as CoffeeScript, since this app was written in CS.

I wrote up a readme with instructions on how to either obtain or download the latest Serenade.js, and how to get and build app.js from app.coffee.

Let me know if there's anything about this approach I should change.

Oh, and I changed app.coffee tabs from spaces :)