[ale] Backup large files to span DVDs

[Alex Carver]

Ok, Google is failing me today.  I've got some large files (larger than
5GB each) that I need to archive to DVD so I'll have to span DVDs.  The
problem is I can't seem to find the appropriate magic incantations to
accomplish this.

The file image and burning tools tools available are genisoimage and
wodim (unfortunately no mkisofs or cdrecord, thanks Debian).

Everything I've found online so far starts wtih the assumption of a
directory full of small files and to make multiple ISOs from those.  But
in this case a single file is bigger than the DVD and there are several
files (about 40GB worth) to archive.