The CMake changes are slightly complicated by the Windows build using
a local copy of some hidapi files, for some reason, instead of using
the hidapi library itself. The Mac version uses hidapi in the same way
as other libraries.
In the CMake files, it is unclear to me whether "elseif (NOT WIN32 AND
NOT CYGWIN)" means the same thing as "elseif (APPLE)", so they are
treated separately in order to avoid breaking other build types.
Martin Cooper