Refactor using Mongo as storage (and a bit better code structure).
A bid of refactoring. Now using a router.

All requests hitting index.php, will detect AJAX and Nexmo requests. Replaced
old data.php and now just spitting out the proxy data from storage. UI can
determine what to hide.
Updated UI.

- Using bootstrap CDN (and Bootstrap 3)
- Changed UI to show message log.
- Updated AJAX data.