nodemap: code to parse the persistent binary nodemap data
We now have code to read back what we persisted. This will be put to use in
later changesets.
Differential Revision: https://phab.mercurial-scm.org/D7844
<entry>
<title>{branch|escape}</title>
<link rel="alternate" href="{urlbase}{url|urlescape}rev/{node|short}"/>
<id>{urlbase}{url|urlescape}#branch-{node}</id>
<updated>{date|rfc3339date}</updated>
<published>{date|rfc3339date}</published>
<content type="text">{branch|strip|escape}</content>
</entry>