codegangsta/cli — pull request #48 by ryansb (2013-12-02 19:30:13+00:00)
Title: string slice flag option formatting

Used to output:
```
-- 'name' -name option -name option%!(EXTRA string=Usage text)
```

Now:
```
--name [] `-name option -name option` Usage text
```
In this case the `[]` denotes that the default is an empty list.