run-tests.py: work when --with-hg is set to system hg
Previously we'd always assume that --with-hg is a script in a user directory,
and would write out a 'python' symlink to the same location. That didn't work
if --with-hg was set to a system installation of hg, e.g. /usr/bin/hg.
Introduce a TMPBINDIR directory which is used to write out the python symlink.
Mercurial's documentation is kept in reStructuredText format, which is
a simple plain text format that's easy to read and edit:
http://docutils.sourceforge.net/rst.html
It's also convertible to a variety of other formats including standard
UNIX man page format and HTML. You'll need to install Docutils:
http://docutils.sourceforge.net/
Use the Makefile in this directory to generate the man and HTML pages.