hgmerge: various cleanups
Details:
- put temporary file names into variables
- make all temporary file names end with random part
- cleanup FileMerge handling
- do not use hardlinks in FileMerge change test (breaks on FAT)
- try harder to keep file mtime unchanged in case of failed merge
<table class="changelogEntry parity#parity#">
<tr>
<th class="age" width="15%">#date|age# ago:</th>
<th class="firstline">#desc|strip|firstline|escape#</th>
</tr>
<tr>
<th class="changesetRev">changeset #rev#:</th>
<td class="changesetNode"><a href="?cs=#node|short#">#node|short#</a></td>
</tr>
#parent%changelogparent#
#child%changelogchild#
#changelogtag#
<tr>
<th class="author">author:</th>
<td class="author">#author|obfuscate#</td>
</tr>
<tr>
<th class="date">date:</th>
<td class="date">#date|date#</td>
</tr>
<tr>
<th class="files"><a href="?mf=#manifest|short#;path=/">files</a>:</th>
<td class="files">#files#</td>
</tr>
</table>