update index.html and .entry.json per recent manifest changes

Every index.html file (for entries) was updated as the tarball download
description was changed to 'download entry source' (though I think this
is a mistake as the C file is described as 'entry source' so it's
ambiguous - that might be fixed soon or it mightn't be until some other
changes are made that need a manifest update).

2012/omoikane/index.html

@@ -308,7 +308,7 @@ href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2012/omoikane/try
 - how to run</li>
 <li><a href="spoiler.html">spoiler.html</a> - SPOILER WARNING</li>
 <li><a href="2012_omoikane.tar.bz2">2012_omoikane.tar.bz2</a> - download
-winning source</li>
+entry source</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>