This uses an extracted pkg2appimage, since it would be tricky to get fuse
to work in the Podman containers.

* The new official homepage is https://sciteco.fmsbw.de/
* My new contact address is rhaberkorn AT fmsbw.de.
* The scintilla-mirror is now also on https://git.fmsbw.de/scintilla-mirror/
* Added CI script for my server on fmsbw.de that builds
  the website.
  It's run in a FreeBSD container, but does not currently
  distribute FreeBSD binaries.

* There are nightly OBS builds, so there is no need to build and distribute them via CI.
* On the upside we can download the packages for the AppImages from a proper (OBS) repository.
* AppImages are now built on Ubuntu 20.04 (instead of 22.04 which was the oldest
  Github runner).

* We can therefore no longer provide 20.04 nightly builds.
  Perhaps I will manually build binary releases for the v2.4.0 release for the last time.
  The PPA will still provide 20.04 of course.
* The AppImages are consequently also built based on the Ubuntu 22.04 packages,
  which are now the oldest supported ones.

Should improve the SciTECO site at the AppImages Hub (appimage.github.io).
We will have to make another PR before the site gets updated.

* You can now specify `--with-scitecodatadir` as a relative path,
  that will be interpreted relative to the binary's location.
* Win32 binaries already were relocatable, but this was a Windows-specific
  hack. Win32 binaries are now built with `--with-scitecodatadir=.`
  since everything is in a single directory.
* Ubuntu packages are now also built `--with-scitecodatadir=../share/sciteco`.
  This is not crucial for ordinary installations, but is meant for AppImage creation.
* Since AppImages are now built from relocatable packages,
  we no longer need the unionfs-workaround from pkg2appimage.
  This should fix the strange root contents when autocompleting in
  AppImage builds.
* This might also fix the appimage.github.io CI issues.
  I assume that because I could reproduce the issue on FreeBSD's
  Linuxulator in dependence of pkg2appimage's "union"-setting.
  See https://github.com/AppImage/appimage.github.io/pull/3402
* Determining the binary location actually turned out be hard and
  very platform-dependant. There are now implementations for Windows
  (which could also read argv[0]), Linux and generic UNIX (which
  works on FreeBSD, but I am not sure about the others).
  I believe this could also be useful on Mac OS to create app bundles,
  but this needs to be tested - currently the Mac OS binaries are
  installed into fixed locations and don't use relocation.

* Since they blacklist Pango among other things, it would use the Pango from the host system with the glib from the AppImage,
  which resulted in a version mismatch on Linux Mint 21.1.
* It is now confirmed to work at least on Linux Mint 21.1.
* The Curses AppImage still bundles libglib as SciTECO should be the only thing referencing its functions.