[syslinux] Supporting WinImage compressed images

[Patrick J. LoPresti]

I am using PXELINUX, ISOLINUX, and memdisk in my project
(http://unattended.sourceforge.net/).  When memdisk gained support for
compressed images, I started using it because it is cool.  I used gzip
to compress floppy.img to create floppy.imz, and all was good.

But now my users are complaining that they cannot use WinImage (a
Windows floppy image editing tool) to edit my floppy.imz files.

I have learned that WinImage does understand compressed floppies, and
it does use a ".imz" suffix for them, but they are not the same as the
files produced by gzip.  They are instead a ZIP archive containing a
single "floppy.ima" (or "floppy.img") file.

In other words, WinImage does not want the .imz file to be a straight
compressed stream; it wants it to be an actual ZIP archive with one
member.

I have found that "gunzip" will handle either of these formats and
generate the original 1.44M data stream.

But memdisk (2.09-pre13) does not recognize it as a compressed file
and chokes.

I realize that compatibility with WinImage is probably a very low
priority.  But is there a chance you add it anyway?  Or to put it
another way...  If I come up with patches to add support for these
archives, might you accept them?

Thank you!

 - Pat