py3: replace sys.platform with pycompat.sysplatform (part 1 of 2)
sys.platform returns unicode on python 3 world. Our code base has most of the
things bytes because of the transformer. So we have a bytes version of this as
pycompat.sysplatform. This series of 2 patches replaces occurences of
sys.platform with pycompat.sysplatform.
.. 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