Changing MAJORDOMO_HOMEDIR to /var

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

Hi all,
policy for most users in pkgsrc is to have a home directory of either
${PREFIX} or ${VARBASE}. Can we please move majordomo to either, so that
it defaults to a place that is supposed to be writeable for packages?

Joerg