tests/test-gendoc-sv.t

py3: port tinyproxy.py to work with Python 3

There were various str/bytes mismatches in the code. This caused
the proxy server to misbehave at run-time. The manifestation
was typically premature socket disconnect from the perspective
of the client.

Differential Revision: https://phab.mercurial-scm.org/D5951

#require docutils gettext

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