Network viz fixes

On the network view, fix the source line's location (x coordinate) and height (y length). Fixes part of #135 , but not all of it. Includes #144 .

![screen shot 2014-06-17 at 3 40 02 pm](https://cloud.githubusercontent.com/assets/526415/3307745/c5b216d4-f670-11e3-9fe6-f7ba76ca4cff.png)