Here are review of diff between old nad new distfiles:
(1) libdata upgrades.
(2) pkg-config files added (vips.pc and vipsCC.pc).
(3) Some small bugs fixed.
(4) Two programs added to build.
(5) Some debug code was removed.
Your could check, that distfile was replaced by visiting
official site and reading news.
Begin autotools sanitization sequence by requiring ports to explicitly
specify which version of {libtool,autoconf,automake} they need, erasing
the concept of a "system default".
For ports-in-waiting:
USE_LIBTOOL=YES -> USE_LIBTOOL_VER=13
USE_AUTOCONF=YES -> USE_AUTOCONF_VER=213
USE_AUTOMAKE=YES -> USE_AUTOMAKE_VER=14
Ports attempting to use the old style system after June 1st 2004 will be
sorely disappointed.