readv()/writev() for input/output. This means that, for instance, you
can readv() data to the end of the string and writev() data from the
beginning of the string without having to allocate or move memory. It
also means that the library is completely happy with data that has
multiple zero bytes in it.
PR: ports/62628
Submitted by: Robert Schlotterbeck <robert@rs.tarrant.tx.us>
