dirstate-item: make sure we set the mtime-second-ambiguous on v2 write
We want to preserve the second-ambiguity alongside the ambiguous mtime. So we
use the decimated flag for that.
note: the C code was already doing so. No change was needed to it.
Differential Revision: https://phab.mercurial-scm.org/D11845
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.