freaks me out. But it turns out we might be able to generalize
a few of the other things RE uses to assemble the package trees
for releases if the DVDs use a naming theme close to what is used
for the CDROMS (disc1, disc2, etc). So change the name to dvd1.
Hopefully this way src/release/scripts/{package-split.py,package-trees.sh}
can be generalized instead of copied-and-hacked.
MFC after: 5 days
b18a67ad04