debugextension: change "testedwith" to a list (BC)
It wasn't a list since the formatter couldn't process a list. We have no
such problem now and the -T option is experimental, so we can change it.
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.