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.

2004/gavare/README.md

@@ -4,7 +4,7 @@
     make
 ```
 
-There are three alternate versions; see [alternate code](#alternate-code) below
+There are three alternate versions; see [Alternate code](#alternate-code) below
 for more details.
 
 
@@ -23,6 +23,10 @@ if you have ImageMagick installed, you can convert it to a jpeg:
 
 and then view `ioccc_ray.jpg` in a graphics viewer, editor or web browser.
 
+**NOTE**: if you do not have ImageMagick installed, see the
+FAQ on "[ImageMagick](../../faq.html#imagemagick)"
+for help.
+
 
 ## Try:
 
@@ -43,10 +47,12 @@ image as well as the anti-alias setting, when compiling.
 The author also provided [on their web page for the
 entry](https://gavare.se/ioccc/ioccc_gavare.c.html) an unobfuscated version that
 was used during development, which we have included in the file
-[gavare.r3.c](%%REPO_URL%%/2004/gavare/gavare.r3.c).
+[gavare.r3.c](%%REPO_URL%%/2004/gavare/gavare.r3.c) (named such because that is
+what they called it).
 
 Finally, the file [gavare.alt2.c](%%REPO_URL%%/2004/gavare/gavare.alt2.c) sets binary mode
-on `stdout` which theoretically should work in Windows.
+on `stdout` which theoretically should work in Windows (if anything works in
+Windows :-) ).
 
 
 ### Alternate build:
@@ -73,7 +79,7 @@ You may of course combine the above two commands and give any combination you
 wish.
 
 This is not possible with the author's version but it is with the alt versions
-(Windows - see below - and otherwise).
+(Windows - see below).
 
 As the Windows version will not compile on most viewers' systems we do not build
 it with `make alt`; instead try:
@@ -93,7 +99,8 @@ Use `gavare.alt`, `gavare.r3` or `gavare.alt2` as you would `gavare` above.
 For users of systems that distinguish between text and binary mode
 (you know who you are), add a library call that specifies binary mode
 for `stdout` as the first statement of `main()`,
-or use `freopen("ioccc_ray.ppm", "wb", stdout);` and do not use redirection.
+or use `freopen("ioccc_ray.ppm", "wb", stdout);` and do not use redirection (or
+see [Alternate code](#alternate-code) above).
 
 A freely distributable command-line version of Microsoft Visual C
 exhibits an optimizer bug when compiling this entry. Disable `/Og` for