[Info-vax] Write Alpha kits on Windows PC for OpenVMS

[Steven Schweda]

> Not an ZIPEXE since they are OpenVMS EXE files and are meant to
> be executed *on* the OpenVMS system for an automatic un-pack. 

   If you have an unzip program (like, say, Info-ZIP UnZip),
then you can use that program to extract the contents of a
self-extracting archive, no matter where you run that unzip
program.  With a poorly crafted self-extracting archive, you
may get an "extra bytes" warning, which is mostly harmless.

   For example:

ITS $ run vms84a_manage-v0200.zipexe
%DCL-W-ACTIMAGE, error activating image vms84a_manage-v0200.zipexe
-CLI-E-IMGNAME, image file ITS$DKA0:[patch.alpha]vms84a_manage-v0200.zipexe;1
-IMGACT-F-NOT_I64, image is not an HP OpenVMS Industry Standard 64 image

ITS $ unzip6l -t vms84a_manage-v0200.zipexe
Archive:  ITS$DKA0:[patch.alpha]vms84a_manage-v0200.zipexe;1
warning [ITS$DKA0:[patch.alpha]vms84a_manage-v0200.zipexe;1]:  88064 extra bytes
 at beginning or within zipfile
  (attempting to process anyway)
    testing: dec-axpvms-vms84a_manage-v0200--4.pcsi$compressed   OK
    testing: dec-axpvms-vms84a_manage-v0200--4.pcsi$compressed_esw   OK
    testing: dec-axpvms-vms84a_manage-v0200--4.pcsi$compressed_hpc   OK
No errors detected in compressed data of ITS$DKA0:[patch.alpha]vms84a_manage-v02
00.zipexe;1.

   A full-function UnZip program offers some potentially
useful options which might be missing from a more minimal
UnZipSFX program, which is typically used to create a
self-extracting archive.