that directory cleaned out before the upgrade. These files aren't
really obsolete, but removing them before installing the new versions
saves the a 'directory was not empty' message in sysinst, which
needlessly worried users.
These lists have been build concatenating distrib/sets/lists/ files for each
NetBSD releases since 1.0, and diffing this with the corresponding 1.4
file.
These files are used to build the /dist/xxx_obsolete files used by sysinst.
fvdl