Problems found with mismatching existing digests for:
distfiles/asclock-classic-1.0.tar.gz
distfiles/asclock-gtk-2.1.10beta.tar.gz
distfiles/asclock-xlib-2.0.11.tar.gz
distfiles/emiclock-2.0.2.tar.gz
Otherwise, existing SHA1 digests verified and found to be the same on
the machine holding the existing distfiles (morden). All existing
SHA1 digests retained for now as an audit trail.
libXext/buildlink3.mk, now that it is included there.
Leave the places where its API version is set or variables from it
are used directly (about 3 packages).