Cleaning up apt cache to optimize disk space
lists folder already exists in root image
apt-get clean no more required

Thanks to tianon's work : https://github.com/docker/docker/blob/master/contrib/mkimage/debootstrap#L64-L87
Merge pull request #1 from josephpage/master

Cleaning up apt cache to optimize disk space
Move Dockerfile over to jessie/Dockerfile and add a wheezy-based version
Merge pull request #2 from infosiftr/wheezy

Move Dockerfile over to jessie/Dockerfile and add a wheezy-based version
Add simple generate-stackbrew-library.sh script
Merge pull request #3 from infosiftr/stackbrew

Add simple generate-stackbrew-library.sh script