Well, that's certainly the more quick fix:

> Activated some stubs for SDL port. Someone should implement them in future, but for now it should at least compile.

If I remember correctly, they are implemented - in ObjectiveC++, in just the files my patch adds to Makefile.am. (I ended up pushing the patch without confirmation, by the way. I think if we want macosx developers to test autotools or CMake we need to remove the xcode project files from the repository.)

Using __APPLE__ to test whether the objectivec++ files containing the real implementations get built and linked is not optimal, but once the CMake build system gets fixed, it should be sufficiently accurate.