normalization changes in APFS

[Philippe Marschall]

Hello

In APFS, likely shipping with macOS 10.13, file names are not longer
stored in nfd [1]. The behaviour now seems very similar to Linux. That
means it's possible to have different two files names in the same
folder that normalize to the same name.

AFAIK currently nfd->nfc conversion happens in the Java NIO file
system layer (JDK-7130915). It may make sense to revisit that.

 [1] http://mjtsai.com/blog/2017/03/24/apfss-bag-of-bytes-filenames/

Cheers
Philippe