build host.

and the OS X port.

on the autobuilders doesn't support it yet.

mingw64 on mingw32).

add set -e to the build-mingw scripts to catch possible regressions.

and SDL_Mixer are needed and are a lot harder to build.

CppUnit is really too large for our needs, would require to be precompiled
for many platforms, in all combinations of debug and release modes, with
additional variants for libstdc++ versions. We replace it with our own
lightweight implementation, LolUnit. Good riddance.

accordingly.