tests/test-gendoc-zh_CN.t

tests: port test-hybridencode.py to unittest

This was done predominantly through keyboard macros in emacs, so it's
not always pretty, but it's enough to make the test easier to work
with. There's a ton of room for improvement in this file, but it would
be labor intensive and error-prone, so I went with the dumbest option
that could work, so as to avoid transcription errors.

Paranoia:
  $ egrep '^    def test' tests/test-hybridencode.py | wc -l
  44
  $ egrep '^    def test' tests/test-hybridencode.py | sort | uniq | wc -l

so I'm pretty confident there aren't any shadowed test methods.

This fixes the test on Python 3.

Differential Revision: https://phab.mercurial-scm.org/D3466

#require docutils gettext

  $ $TESTDIR/check-gendoc zh_CN
  checking for parse errors