match: avoid rust fast path if the matcher was tampered with
Otherwise the fast path does not respect the modifications made
by the extension (concretely largefiles, but other extensions can
start using that too)
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.