Oops, I intended on mentioning this in the pull request comment.  For some reason, the authors of the extension decided to always return ISN's in a dash-separated format. The dash-separated format isn't required for INSERT, SELECT, etc. It seemed like a bizarre decision considering how infrequently I've personally seen EAN's displayed in this fashion. The same process occurs in `#ean13_to_string`, though, looking at it again, I'm relatively certain it is unnecessary in that method.

For all of my use cases, the `-`'s would have to be stripped, so I chose the selfish path. Let me know if you'd like me to remove.