12-02-14 vdelhdr.h,vdio.c: apply patch from philippe.bergheaud

04-03-14 vdelta.h: #if !_DLL => #if !defined(_DLL) to handle empty value

08/11/95 version 2.0 -- new delta layout but old update recognized

04/24/95 back out of latest version -- incompatible deltas generated