Consider either adding a command line tool or splitting out into a framework

[dempseyatgithub]

Pull request #15 proposes factoring the extractor pieces into a separate framework. My comments there describe my initial thoughts about that.

It may keep the complexity of the project reduced by adding a command line tool target to the project itself - providing the desired functionality of a command-line tool without the overhead of maintaining a separate framework for a small number of files.

[dempseyatgithub]

Updated the issue title to reflect the decision. Will add a separate target to the project for a command line tool. That target will include the necessary files directly. Have sent jsorge a one-off copy of my initial implementation, which consists of three files, so not too much added complexity to the project.