hgweb: pass strings in WSGI environment correctly from wsgicgi
According to PEP 3333, the strings in the WSGI environment must be translatable
to bytes using the ISO-8859-1 codec.
.. Common link and substitution definitions.
.. |hg(1)| replace:: **hg**\ (1)
.. _hg(1): hg.1.html
.. |hgrc(5)| replace:: **hgrc**\ (5)
.. _hgrc(5): hgrc.5.html
.. |hgignore(5)| replace:: **hgignore**\ (5)
.. _hgignore(5): hgignore.5.html