-# summary of how this script can be called:
-# * <new-preinst> `install'
-# * <new-preinst> `install' <old-version>
-# * <new-preinst> `upgrade' <old-version>
-# * <old-preinst> `abort-upgrade' <new-version>
-# for details, see http://www.debian.org/doc/debian-policy/ or
-# the debian-policy package