doc/common.txt

Fix --blacklist when --jobs > 1 in run_tests.py.

The options parsing logic replaces the options.blacklist initial value,
a list of filenames, with a dict of test names to filenames.  When
runchildren rebuilds the command line to launch child processes the dict
is flattened and provided as a malformed argument when a filename is
expected.

Fix is to remove the blacklist option from child invocations since the
filtering is handled in the parent anyway.

.. 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