chgserver: implement validate command
validate will load the repo config and check if the server has up-to-date
config to continue serve the client. In case it does not, the server will
send instructions to the client about what to do next, including to retry
with a different address or to unlink an outdated socket file to stop an
old server.
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.