It was substituting _ which didn't match what pungi uses for creating
the DVD. Make things consistent and use - as the replacement character.
(cherry picked from commit 372bef945f2addbf66c35bce8439f3508ee2ab8a)
Resolves: rhbz#1757338
...turns out you can't just have a single template file, because lorax
just picks a single directory and expects all the data it needs to be
there. Sigh.
So this adds all the rest of the files, plus some Makefile machinery for
generating a tarball and updating the specfile after you've checked in
changes. See README for details.