More html files of 2004 fixed

Some bug statuses have been changed so the bugs file was also updated
(some removed, some added).

The manifest of 2004/hibachi was fixed some.

The alt_url of 2004/gavare was fixed which required a rebuild of
authors.html.

For 2004/gavin a proper link to QEMU was added. It strikes me as it
possibly being a good idea to have an FAQ about QEMU (as it is not just
2004/gavin that might benefit from it) but I don't know and in any case
I have zero experience with it.

The entries 2004/gavare, 2004/gavin and 2004/hibachi have been checked
for format / display issues. This would suggest that the next entry to
look at is 2004/hoyle.

authors.html

@@ -1687,7 +1687,7 @@ Location: <a class="normal" href="location.html#SE">SE</a> - <em>Sweden</em>
 <br>
 URL: <a class="normal" href="https://gavare.se">https://gavare.se</a>
 <br>
-Alternate URL: <a class="normal" href="https://gavare.se/ioccc/ioccc_gavare.c.html">https://gavare.se/ioccc/ioccc_gavare.c.html</a>
+Alternate URL: <a class="normal" href="https://gavare.se/ioccc">https://gavare.se/ioccc</a>
 <br>
 author_handle: <a class="normal" href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/author/Anders_Gavare.json">Anders_Gavare</a>
 <p>