fix - non utf-8 encoded txt file decode correctly

[ghost]

Extracted strings from non utf-8 encoded txt file are broken.

1. detect encoding
2. decode correctly

[dbashford]

Missing package.json updates. Do you have a file I can use that you may have used for testing purposes? I can throw together a test.

[ghost]

Added non utf8 text test case.
Euc-jp encoded file('これは非UTF8 テキストファイルです' ('this is a non utf8 text file'))
Modified package.json.