Dealing with IOS "High  Sierra"  problem:  Apple's  (mis)implementation  of
UTF-8  encoding  rules causes file names from other system to be "illegal",
and much Apple software (including C libraries) refuses to do anything with
files that have illegal names.

Example:

| /Users/jc: rsync -CHlprtOuvK --exclude-from=w/music/abc/.rsExclude john-chambers.us:w/music/abc/ w/music/abc/
| receiving file list ... done
| rsync: link "/Users/jc/w/music/abc/mirror/geocities.com/novairishsession/bwreels/%100:Fearghal_�_Gadhra.abc" => mirror/geocities.com/novairishsession/bwreels/%100:Fearghal_%D3_Gadhra.abc failed: Illegal byte sequence (92)
| rsync: link "/Users/jc/w/music/abc/mirror/geocities.com/novairishsession/bwreels/%107:Reel_de_Montr�al.abc" => mirror/geocities.com/novairishsession/bwreels/%107:Reel_de_Montr%E9al.abc failed: Illegal byte sequence (92)
| rsync: link "/Users/jc/w/music/abc/mirror/gradcenter.marlboro.edu/abc/canadian/Cotillion_�_Huit.abc" => mirror/gradcenter.marlboro.edu/abc/canadian/Cotillion_%E1_Huit.abc failed: Illegal byte sequence (92)
| rsync: link "/Users/jc/w/music/abc/mirror/gradcenter.marlboro.edu/abc/canadian/Reel_B�atrice.abc" => mirror/gradcenter.marlboro.edu/abc/canadian/Reel_B%E9atrice.abc failed: Illegal byte sequence (92)
| rsync: mkstemp "/Users/jc/w/music/abc/mirror/geocities.com/infants_catiau/renaissance/.%11:Branle_des_Lavandi�res.abc.dxWiDq" failed: Illegal byte sequence (92)
| rsync: mkstemp "/Users/jc/w/music/abc/mirror/gradcenter.marlboro.edu/abc/playf/.Hit_and_Miss_Daphne_�.abc.1sdou8" failed: Illegal byte sequence (92)
| 
| sent 299 bytes  received 5988772 bytes  1088922.00 bytes/sec
| total size is 667827790  speedup is 111.51
| rsync error: some files could not be transferred (code 23) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-52/rsync/main.c(1404) [generator=2.6.9]
 
This makes rsync totally fail for some filenames on the remote system, even
if it's an earlier version of IOS that accepted them.