Enable building of DEB file.

[harp37]

To begin our discussion on DEB packing:

"I'm not necessary sold on the virtues of carrying the debian configuration in the tarball itself. What is the advantage of that? Isn't it cleaner to separate the packaging from the code?"

I have seen this done both ways. Mostly it depends on how we are going to release new versions of the game itself. I don't think the final result is cleaner without the Debian configuration in the tarball. Although the tarball itself may look dirtier, I believe it is easier for developers. Reasons being: we provide changes easier (Debian packing updates rather quickly in my experience), we can work out problems (almost) effortlessly, and we can test alternatives later if it is decided that it could be improved. But I know less about Debian packing than other things, so I might need to conduce better alternatives on the back burner.