Issues:
- MM0 needs separate subset of libc and not link with libposix
- FS0 needs separate subset of libc and not link with libposix
- libposix need transforming into a full-blown uclibc for test0
- libc really is a pseudo-libc that needs to be replaced as above.
- Done some hacking to avoid conflicts between pseudo-libc and libposix headers.
Now system working as original, (e.g. execve etc. working)