largefile: synchronise the dirstate within a `parentchange` context
Semantically these changes are made to adjust the dirstate after a commit, so it
should be in a `parentchange` context.
Differential Revision: https://phab.mercurial-scm.org/D11103
<li class="parity{parity}" data-node="{node|short}">
<div class="fg">
<span class="desc">
<a href="{url|urlescape}rev/{node|short}{sessionvars%urlparameter}">{desc|strip|firstline|escape|nonempty}</a>
</span>
{alltags}
<div class="info"><span class="age">{date|rfc822date}</span>, by {author|person}</div>
</div>
</li>