Remove the advertising clause from the Regents of the University of
California's license, per the letter dated July 22, 1999.
Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic number the clauses 1 through 3,
so follow suit to make comparison easier.
Remove the advertising clause from the Regents of the University of
California's license, per the letter dated July 22, 1999.