Moved userspace libc to posix container directory.

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)

containers/posix/fs0/src/memfs/memfs.c

@@ -192,7 +192,7 @@ struct superblock *memfs_get_superblock(void *block)
 		return 0;
 	}
 	if (sb->magic != MEMFS_MAGIC) {
-		printf("%s: Magic number not match: %s\n", __FUNCTION__, sb->magic);
+		printf("%s: Magic number not match: %u\n", __FUNCTION__, sb->magic);
 		return 0;
 	}