Pull requests for today

Hi all, As you can see, I've been very distracted from work this evening :) Binary convex hull goodness: https://github.com/scikits-image/scikits-image/pull/75 Super-fast re-building of the package for developers, using MD5 hashes of Python files: https://github.com/scikits-image/scikits-image/pull/74 Coin dataset--almost as good as the real thing: https://github.com/scikits-image/scikits-image/pull/76 Please have a look, and let me have your critical yet witty feedback on GitHub :) Cheers Stéfan