reference to the "deflate" compression module. This can be used to
build a very small zcat for things like install media. (An example
of such a small zcat may be found in src/distrib/utils/zcat).
included without the other, private header files. Only zlib.h
should be installed in /usr/include; all others are private.
The Makefile has a "test" rule to verify that minigzip.c can
be compiled using only zlib.h (and that it actually works).
Note: This file has extensive modifications.