I broke my promise: again, you'll have to purge OpenGFX before upgrading to the latest OpenTTD in extras-devel (and which I plan to finally move to normal extras soon, since I think I got the scrolling bug fixed).

The reason is that OpenGFX is now packaged as "openttd-opengfx", since I am now following the Fedora packaging (the only distro that is packaging OpenGFX too).
An important change is that the source package for openttd-opengfx now contains actual sprite sources and not the final data package, which means ideally in the future I'll be able to make patches for Fremantle to contain bigger graphics.

Of course, with this update, OpenTTD in extras-devel (and soon extras) can now work without any of the non-free files. It can still work with the non-free files, if you want, of course.