PoorMan: Add dual-stack IPv6 support

This change adds dual-stack IPv6 support to the PoorMan web server,
which will listen on all available IPv4 and IPv6 addresses and
respond to both.

This change also does some necessary plumbing to support the
output of nicely-formatted IPv6 addresses for request logging.

Change-Id: I0ce7691222f0233e2e098d67e6293b9e58d7486d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3539
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

Patch by Ma Jie: Basically - make Poorman (the webserver) work. Libhttpd from
Jef Poskanzer is providing the backend, but had to be adopted in some ways.
Other issues in Poorman have been resolved.

When testing the license integration, I stumbled over some AboutSystem bugs,
basically clicking licenses would not open them. I fixed those in this patch,
sorry for mixing that up.

Note to Ma Jie: I changed the encoding of the libhttpd files to UTF-8!
(This affects only the (C) glyph.) Thanks a lot for your awesome work on
Poorman, it's really appreciated!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29906 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Ma Jie: Basically - make Poorman (the webserver) work. Libhttpd from
Jef Poskanzer is providing the backend, but had to be adopted in some ways.
Other issues in Poorman have been resolved.

When testing the license integration, I stumbled over some AboutSystem bugs,
basically clicking licenses would not open them. I fixed those in this patch,
sorry for mixing that up.

Note to Ma Jie: I changed the encoding of the libhttpd files to UTF-8!
(This affects only the (C) glyph.) Thanks a lot for your awesome work on
Poorman, it's really appreciated!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29906 a95241bf-73f2-0310-859d-f6bbb57e9c96