Async client-side rendering

Rewrote part of the client side to dismiss using the timeout function to block the client. The client will instead call a function with a callback which fires of a asynchronous GET request to the API. When the onreadystatechange handler is called, the callback function provided is called with the graph object as argument.

0.4

The previous release was dependent on a recurring cron job to avoid that the client had to refresh the website.

With this release the rendering of the website on the client side is blocking for 2 seconds. This dismisses the use of a recurring cron job, and reduces the number of hours that this application consumes from the Heroku free limit.