apreq documentation

Hi,

with the recent release of apreq 2.17, the documentation ([1]) looked a 
bit out dated.
The main page speaks about 2.13!


It was last generated with Doxygen 1.5.6 nearly 12 years ago.
The link to the documentation can be found at ([2]).


Tweaking things a bit (see my recent commits), and using Doxygen 1.9.1, 
it now looks much better.
I've tried to re-implement the same layout as before, so the standard 
1.9.1 Doxygen layout has been slightly customized.

You can give it a try at:
http://home.apache.org/~jailletc36/apreq_doc_2.17/docs/html/index.html

If we reach an agreement on the new look, it can be uploaded on a.o.org 
to refresh the look and be more consistent with the rest of the website.


I'm not sure that the 2.17 Changelog is complete.
If I'm right, this release is mainly about a CVE, but it is not listed 
and [3] gives hints about other changes in the past months/years.


Comments and bug hunting welcome :)

CJ


[1]: https://httpd.apache.org/apreq/docs/libapreq2/index.html
|2]: https://httpd.apache.org/apreq/
[3]: https://svn.apache.org/viewvc/httpd/apreq/trunk/library/?sortby=date