Improve error message for unknown revlog flags.
Old: unknown flags 120000 for ...
New: unknown flags 0x0012 for ...
<table class="slogEntry parity#parity#">
<tr>
<td class="age">#date|age#</td>
<td class="author">#author|obfuscate#</td>
<td class="node"><a href="#url#rev/#node|short#{sessionvars%urlparameter}">#desc|strip|firstline|escape#</a></td>
</tr>
</table>