Closes #588.

Mimic the Makefile by outputting html + js instead of LLVM IR.

src/core.c does explicitly skip including <camera.h> on Android
and tests fail. Therefore skip these failing tests.

Closes #507.

They were disabled because they failed to build,
but this patch set fixes the build on Linux and macOS.

This doesn't apply to the AppVeyor build on Windows yet;
it currently fails at linking with OpenAL.

Some people might find this handly