Copyright claim

[bowlofeggs]

While reviewing #63 I noticed that this project doesn't seem to make a copyright claim. I think the recommended practice is to put a copyright header on each file (at least, I feel like I remember the FSF making that recommendation), though I've also seen precedent for making a single COPYRIGHT file in the root of the repo. I don't think it's that important how it's done, but it probably is important to claim copyright on this code in some fashion.

[tyll]

good point, I believe this is also mentioned in the licensing guidelines, in the gpl howto and best practice.