verify: report first bad changeset - add linkrev and file arguments to err - track lowest reported linkrev in err - find linkrev in a couple cases - sort linkrevs when reporting a bunch of errors against a file - tidy up lots of messages - make more robust against damaged indexes - report first bad changeset if an error is encountered

<table class="slogEntry parity#parity#">
 <tr>
  <td class="age">#date|age#</td>
  <td class="author">#author|person#</td>
  <td class="node"><a href="#url#rev/#node|short#{sessionvars%urlparameter}">#desc|strip|firstline|escape#</a></td>
 </tr>
</table>