Request: Add a dj_zlib package

I discovered that fdnpkg contains it's own version of zlib, and it is outdated: 1.2.8. DJGPP web site contains a binary file for latest version: 1.2.12.

I suggest that we add a package dj_zlib, that will be a common place for all packages needing it. Well... .exe will still have to include it, because the is no DLL for DOS (as far as I know). So space gains will be limited to not include zlib source code in each package neeeding it.

This will allows to recompile fdnpkg with it... possibly allowing to use new compressors (fixing a problem when using my Linux compress zip files).