Adding a unique identifier to the OS taxonomy view.

#3952 
Before the change:
![before](https://f.cloud.github.com/assets/1222368/1233032/beb2907c-2900-11e3-8a5c-f8e4c7ed871c.png)

After the change:
![after](https://f.cloud.github.com/assets/1222368/1233033/c51f7650-2900-11e3-9c12-3b38b594ff1b.png)