Extract differ in util to separate library

[Andarist]

Willing to work on this, but as you are the author of the code it would be good if you could create a repository against which I could create a PR.

[developit]

Definitely a fan of that idea!

[Andarist]

As mentioned - I'd like you to create repo for this, I can send a PR with everything setup correctly for publication etc.

[developit]

Yup, just need to make sure I'm good to create a repo haha.