Fixes #664 - Refactor total progress area on dashboard

I refactored so that the same information that is shown for each project is shown for the total - hours worked, hours assigned, and a visual bar.

![dashboard3-remaining](https://f.cloud.github.com/assets/1759718/514507/9105d86c-be59-11e2-9560-2cc6c18df039.png)

![dashboard3](https://f.cloud.github.com/assets/1759718/514490/41ac9896-be59-11e2-8536-8700c022ee72.png)

See #664.