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
#header#
<title>Mercurial repositories index</title>
</head>
<body>
<h2>Mercurial Repositories</h2>
<table>
<tr>
<td>Name</td>
<td>Description</td>
<td>Contact</td>
<td>Last change</td>
<td> </td>
<tr>
#entries%indexentry#
</table>
#footer#