shelve: look for shelved node in the repository before unbundling
This prepares the version of shelve that would not strip the shelved node from
the repository. If we have the node information, search for it in the
repository and only fallback on unbundling if it is missing.
To be able to find such nodes, we operate on an unfiltered repository.
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.