hgweb: display fate of obsolete changesets
Operations that obsolete changesets store enough metadata to explain what
happened after the fact. One way to get that metadata is showsuccsandmarkers
function, which returns a list of successors of a particular changeset and
appropriate obsolescence markers.
Templates have a set of experimental functions that have names starting with
obsfate. This patch uses some of these functions to interpret output of
succsandmarkers() and produce human-friendly messages that describe what
happened to an obsolete changeset, e.g. "pruned" or "rewritten as
6:
3de5eca88c00".
In commonentry(), succsandmarkers property is made callable so it's only
executed on demand; this saves time when changeset is not obsolete, and also in
e.g. /shortlog view, where there are a lot of changesets, but we don't need to
show each and every one in detail.
In spartan theme, succsandmarkers is used instead of the simple "obsolete:
yes", in other themes a new line is added to /rev page.
<tr>
<td class="diffstat-file"><a href="#l{fileno}.1">{file|escape}</a></td>
<td class="diffstat-total" align="right">{total}</td>
<td class="diffstat-graph">
<span class="diffstat-add" style="width:{addpct}%;"> </span>
<span class="diffstat-remove" style="width:{removepct}%;"> </span>
</td>
</tr>