get a tarbal from git for slackbuild

I know nothing about git.

However, this is how I managed to download the most recent version of openbox from git, and make it ready for the slackbuild script.

1. git clone git://git.openbox.org/mikachu/openbox
2. cd openbox and run bootstrap
3. cd .. and rename openbox to the correct version, e.g. openbox-6.2.
4. tar cf openbox-6.2.tar openbox-6.2
5. gzip openbox-6.2.tar
6. cp openbox-6.2.tar.gz to slackbuilds builddir and open the slackbuild script and change the VERSION variable.