justified output needs some spaces between columns

With long topic names, adjacent columns run into each other.  For example, from `kafkat set-replication-factor`:

```
very.very.very.very.very.very.very.long.name64          [10130493, 263605528]
very.very.very.very.very.very.very.long.name65          [101304171, 382818071]
```
