... and now the application has been updated again, tested working
without X11 (thanks Bob). It was indeed libSDL.dylib that had an X11
dependency that SDL.framework does not have. Since I had no real reason
for changing which of them I used I've now gone back to building exactly
the same way I built the v1.8.0 release but with the latest sources.
https://dl.dropboxusercontent.com/u/669647/Hatari.app.zip
If no other show stoppers appear I should be able to make a release when
needed, with some caveats that my travel schedule might keep me offline
for 24 hours every now and then.