Path normalization tests for Unicode variants on multiple
platforms and filesystems.  For all testing details, see 
the top-of-file docstring in _TEST.py, which is copied to 
all platform subfolders.  Each subfolder has console output
in _TEST-output.txt and path walks in LOGS/*deltas-apply*.txt.

About the zipfiles:

Each platform also has a results zipfile, unzipped to
create platform folders here.  This is necessary because
Finder on macOS, the main dev platform, silently discards
files whose names don't follow an arbitrary Unicode-variant
rule, when copying raw content from an exFAT drive.  In 
fact, Finder won't even display these files on the drive, 
despite the fact that they are known to be present.

For reference, all other platforms tested handle these files
correctly; macOS itself can store all the files that Finder 
discards; and Finder's own unzip (Archive Utility) retains 
the files that Finder hides.  Anti-interoperable, that!

To work around this harsh--and ludicrous--Finder constraint 
on macOS, results are zipped with ziptools on test platforms, 
and unzipped with ziptools on macOS.  ziptools is a portable
Python-coded tool, at https://learning-python.com/ziptools.
The macos/ folder was also zipped for symmetry, but not 
unzipped here (a Finder copy suffixed on its native soil).