Log Message:
Add missing krb5.bl3.mk; force use of internal libroken to avoid PLIST
divergence.

XXX: This package still cannot be used with pkgsrc heimdal because
XXX: it conflicts on bin/kpasswd and bin/pagsh. This should be fixed,
XXX: as replacing native kerberos's kpasswd binary on the PATH isn't
XXX: really good either.