show a colored bar to indicate health status


![Screen Shot 2013-03-08 at 14 36 46](https://f.cloud.github.com/assets/411/236613/52a508da-87f5-11e2-9a5e-5baaeb744518.png)
To see how healthy the tanks are, I implemented a colored bar below the name of the tank to show how close he is to dying. Hope you like it. Comments are welcome.