[PATCH 3 of 4 v2] run-tests: add support for RTUNICODEPEDANTRY environment variable

[timeless]

Augie Fackler wrote:
> Can you point me to that series as a URL? I'd like to get an idea of
> where this is going. I'm not sure how I feel about the variable yet,
> but seeing the rest of the work involved would help.

https://bitbucket.org/timeless/mercurial-crew/commits/all?search=%3A%3Ab1273033cbe8

i'm not terribly attached to _asbytes over _bytespath
but _bytespath is inaccurate when talking about environment and args
and a few other things