Add a Statusboard Endpoint

I made a start at a page to render JSON to power our Statusboard (JSON is formatted per http://panic.com/statusboard/docs/graph_tutorial.pdf).

I wanted billable hour totals (eventually maybe more stuff) for all projects, which isn't fun to get out of Harvest. 

If you know of another way, let me know. Also, plz add me to the Heroku project. 

We'll probably need to come up with a more clever way to refresh totals. I hope everyone puts in their hours the day they worked them, but I know from experience that's not always the case.