I found that the icon used by DOSBox-X comes from
https://www.vogons.org/viewtopic.php?p=79575#p79575
Which apart from Windows and Mac icons also included a SVG icon
which is preferred on Linux, and looks nicer. So add the SVG icon
and update 'make install' and make-rpm.sh to use it.
The SVG icon is placed in contrib/icons
p.s. I found that the tar operation in make-rpm.sh blindly assumes
the directory containing the tree to be named "dosbox-x", instead
of just the current directory, it effectively will tar
../dosbox-x even if your in, say, dosbox-x.clone to keep different
trees apart... I did not change this for now, but it is something
to watch out for.
The general idea is to clean up the root directory of the tree
a bit, and to possibly prepare to support flatpak in the future
without adding more files to the root.
Both "make install" and make-rpm.sh worked after these changes.
My idea was also to move src/dosbox.png to contrib/icons/dosbox-x.png
And to move any Windows and macOS specific packaging files to
contrib/windows and contrib/macos respectively, but I will not do the
latter two myself as I cannot test it.
This is also similar to how dosbox-staging has it's tree layout.
If there is no objection, I will however move src/dosbox.png and
update any references to it to point to the new location.
