zlib 1.2.12.
Files not required by OpenMPT have been removed.
OpenMPT specific changes:
 *  A work-around for <https://github.com/madler/zlib/issues/606> been applied
    in deflate.h.
 *  <https://github.com/madler/zlib/commit/eff308af425b67093bab25f80f1ae950166bece1>
    and
    <https://github.com/madler/zlib/commit/1eb7682f845ac9e9bf9ae35bbfb3bad5dacbd91d>
    for CVE-2022-37434 have been applied.
 *  iowin32.c has been modified to only use Windows 8 WinRT API when actually
    compiling for Windows 8 or later.
 *  minizip has been modified to check for allocation failure. A similar fix
    has been proposed upstream: <https://github.com/madler/zlib/pull/566>
 *  All custom modifications are marked with /* OpenMPT */
 *  For building, premake is used to generate Visual Studio project files.
    See ../build/premake/ for details.
No further changes have been made.
