We actually haven't been testing in 0.4 at all for quite a while
now. Since this is a standalone base game without complex
interdependency relationships, there isn't really any need to
maintain compat with old versions of the engine. Players can
upgrade to play; keeping a separate copy just to play on old 0.4
servers is even still an option.
There is some internal cruft that has been building up to support
0.4, and this allows us to purge most of it. The larger benefit
may come when we're able to remove line_of_sight in favor of the
more efficient raycast (still yet to be done).
