doc/common.txt

setup.py: Add 'mercurial' as include dir for the inotify compiler.

This patch adds access to util.h for the inotify C module by adding the
"mercurial" directory as an include dir, enabling access to the macros defined
in util.h.

.. 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