These patches are designed to get a fresh copy of libxmp 4.4.1 in line with
MegaZeux's needs. Apply them in order (01, 02, ...) for best results. Then, copy
Makefile.megazeux to the contrib/libxmp directory.

After the depacker and format patches are applied, the depackers folder and all
removed format loaders should be deleted.

Patch summary
-------------

01: Initial integration patch. Suppresses debug messages, forces static build.
02: A hack required so unistd.h wouldn't cause issues. Should be revised.
03: Fixes https://github.com/cmatsuoka/libxmp/issues/97. This has been merged
    upstream in PR https://github.com/cmatsuoka/libxmp/pull/98.
04: Fixes https://github.com/cmatsuoka/libxmp/issues/98. This has been merged
    upstream in PR https://github.com/cmatsuoka/libxmp/pull/99.
05: Disables USE_VERSIONED_SYMBOLS. Required to get our hacked libxmp to link
    on unix platforms. Ideally these platforms will eventually dynamically link.
06: Fixes https://github.com/cmatsuoka/libxmp/issues/102 (global sample volume)
    and https://github.com/cmatsuoka/libxmp/issues/103 (sample vibrato).
07: Removes the depackers (messy).
08: Removes the less common formats that weren't supported by libmodplug.
09: (by Spectere) cleans up part of the depacker removal mess. Merge with 07.
10: (by Spectere) cleans up more of the depacker removal mess. Merge with 07.
11: (by Spectere) cleans up more of the depacker removal mess. Merge with 07.
12: (by NoSuck) adds https://github.com/cmatsuoka/libxmp/pull/105 (xmp_set_row),
    putting libxmp's support for setting MOD_POSITION in line with libmodplug.

Unix note
---------
The only things preventing unix builds from just dynamically linking libxmp are
A) the .it format patches and B) xmp_set_row. Presumably, the latter will exist
in later releases of libxmp, and .it handling might be replaced with libit216 in
MegaZeux 2.92.

--Lachesis
