Nawqaan-288 - Pie chart functionality almost complete

Still need to hear from Jeff on what to do with nulls. In the meantime, I'd like this merged so we can put it up on dev to play with the features already implemented
We should do error handling here. Other parts of the app have been throwing Errors and using the window.onerror handler we defined to catch and report them. If curious, there are browser inconsistencies with window.onerror: http://danlimerick.wordpress.com/2014/01/18/how-to-catch-javascript-errors-with-window-onerror-even-on-chrome-and-firefox/