Adds bztar format to generate .tar.bz2 tarballs
Uses the -f argument to overright old tarballs automatically, I am
assuming that if the old tarball was wanted it would have been moved or
else the version number would have been changed.
Uses the -9 argument to bzip2 and gzip to use maximum
compression. Compress uses the maximum compression by default.
Tests for correct value for the 'compress' argument of make_tarball. This
is one less place for someone adding new compression programs to forget to
change.
Initial revision is pretty limited; it only knows how to generate "dumb"
binary distributions, i.e. a tarball on Unix and a zip file on Windows.
Also, due to limitations in the installation code, it only knows how to
distribute Python library code. But hey, it's a start.
