Add potential solution to regex match issue.

Here's my fix — it worked for nearly every case except for `ISO-2022-JP-2`, but here's the catch: the failure happened *inside of the Minitest*.

```
Encoding::ConverterNotFoundError: code converter not found (UTF-8 to ISO-2022-JP-2)
```

[Ruby 2.1.0 doesn't support](http://stackoverflow.com/questions/23852059/convert-from-iso-2022-jp-2-to-utf-8-in-ruby-2-1) that encoding, so I had to install the `iconv` gem and fall back on an alternate conversion method if it failed.

Otherwise, the simple modification to the `non_empty?` method works just fine.