hgweb: link to revision by node hash in paper & coal...
hgweb: link to revision by node hash in paper & coal
Unlike other styles, paper and coal had only one link to current revision: in
the sidebar. Since those links now use symbolic revisions after 3bb6f5f478a7,
it's nice to have a link that allows going from /rev/tip to /rev/<tip hash>,
for instance. Let's make the node hash in the page header that new link.
