Add @SorryAboutThat annotation

```
Currently, the library is a big win! But I think it's still missing a useful 
annotation. @SorryAboutThat would be a great addition to express desperation to 
coworkers, and we couldn't do it another way.

Thanks for such a useful tool!
```

Original issue reported on code.google.com by `bmathus` on 12 Dec 2013 at 1:07
