This contains a local copy of parts of libmspack.

Parts (lzxd.c and various header files) were originally lifted from
libmspack and modified to support the LZX DELTA format.

The "file format" support in oab-decompress.c was developed as part of
Evolution-EWS, and a mostly rewritten version was later submitted for
inclusion in libmspack upstream.

If you have a sufficiently recent version of libmspack, none of the
code in this directory will be used. Instead ews-oab-decompressor.c
in the parent directory will invoke the decompressor in libmspack.