revlogdeltas: extract _getcandidaterevs in a function
The logic barely uses the object it is attached to. This is an important
function that we will clean up in the coming changesets. Moving it at the top
level helps us with that cleanup.
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.