Adding to MDBudgetViz

Hey Team,
I wanted to contribute to the project. So, I:

1) Added a doughnut chart for revenue sources, with links on corresponding pages

2) Added spending break downs to the expenses doughnuts page (but not the bar page) and the revenues doughnut page that I made. 

3) Filled in the correct percentages on the "Spending Bar" page, which is one of the open issues. 

Hope you are able to use this and that it helps.