POSIX support with ByteString file paths and environment strings.

This module exports exactly the same API as System.Posix, except that all file paths and environment strings are represented by ByteString instead of String. The System.Posix API implicitly translates all file paths and environment strings using the locale encoding, whereas this version of the API does no encoding or decoding and works directly in terms of raw bytes.

Note that if you do need to interpret file paths or environment strings as text, then some Unicode encoding or decoding should be applied first.