python-argparse (1.1) shipped with debian squeeze is bugged and doesn't work with installsystems needs
python-argparse 1.2.1 (last upstream version) was backported into squeeze and we need it.

argparse is available in python2.7 (archlinux) and on python-argparse package in debian. So
we add a dependency to this package.

We need installsystems is functional on squeeze systems...

So we needs to embed:
- argparse 2.7.1 (not in python2.6)
- progressbar 2.3 (not in debian squeeze)

This commit introduce remote repository and file accross ssh

We now use PipeFile to handle complex file type and compute md5 and filesize.

This commit add the following features in installsystems:
- A download progress bad
- check size before download
- check size after download
- check md5 after download

This will help remi to be cool and save some day in his life