script/download_and_untar.sh incompatible with zc.buildout installation

Created by: 1kastner

Like this the shell script does not work in case you used zc.buildout. Even the shell script is not shipped. I could use it and modified it for my purpose like this: https://gist.github.com/1kastner/587ec3b395be715c3461 If it could be shipped in the normal bob buildout process and further adjusted for that, that could be great!