manifests: push down expected node length into the parser
This strictly enforces the node length in the manifest lines according
to what the repository expects. One test case moves large hash testing
into the non-treemanifest part as treemanifests don't provide an
interface for overriding just the node length for now.
Differential Revision: https://phab.mercurial-scm.org/D10533
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.