Use CommonJS-style modules and browserify instead of requirejs
Add support for accessing CPA from node.js

- Expose all methods via node.js and the browser
- Swap in jQuery browser shim for XHR requests in the browser
- Use common HTTP request facade from radiotag.js
Add node instructions and contributor info
Merge pull request #2 from radiodan/browser-and-node

Refactor to work in node.js and the browser