Set source format to 3.0 (quilt)

The previous hopes were shattered. We gotta do things another way.
Add Makefile to create actual source package

I *really* don't want to include the MAD-X sources within this repository.
The Makefile takes care to automatically download and extract the sources,
and finally merge them with the debian directory to create the source package.
Set distroseries to precise

Apparently 'unstable' is not a valid Ubuntu distro series. This repository
is created to speed up Travis tests, therefore the series is set to 'precise',
since Travis currently uses Ubuntu 12.04 LTS (precise pangolin).