Basic bytevector FFI support.
Adding sexp_bytes_maybe_null_data macro for bytevector FFI support.
Adding send and receive support, with an example of how to use them with udp.
Fixing (chibi net) docs.
sexp_c_string returns #f for NULL
Handle missing user/group password info in tar-create.
Ensuring parent directories in tar-create.
Better error message in parse-func.
"--" doesn't necessarily imply no script.
Fixes issue #237.