Python 2 dependency backports.os failures on Windows

[jayvdb]

I noticed some fairly significant failures in the test suite of backports.os which is used by pyfs on Python 2.

https://github.com/PiDelport/backports.os/issues/13

I am not able to easily ascertain the impact it would have on pyfs, but it does appear that those bugs are exposed through pyfs to its users.

I've looked at the code briefly, and it is quite complex - my guess is it isnt a quick fix, and not many people motivated to fix it.

As Python 2 is nearing EOL, it might be sufficient to prominently summarise the problems for Windows Python 2 users, so they can attempt to avoid names which trigger the bugs when using pyfs.

[willmcgugan]

I'd agree if it can't be fixed, then documenting it might be the only option.

But I'd like to know a bit more about the issue. Without knowing what paths fail to decode I wouldn't know what to add to the docs.

I've subscribed to the issue for now. I'll revisit this once I have all the details...