Order taxons with hierarchy in mind.

### Before
![screen shot 2014-03-07 at 10 56 32 am](https://f.cloud.github.com/assets/193112/2353545/26d28d40-a5a4-11e3-8810-161dfb548476.png)

### After
![screen shot 2014-03-07 at 10 56 15 am](https://f.cloud.github.com/assets/193112/2353546/2a42fcee-a5a4-11e3-8ec0-06715e4e0f52.png)