Changes to unix

Changes to unix:
commit 18a54fa5ac929d07baaaa6fb9669632a10fd78d7
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Fri Nov 8 16:33:11 2013 +0100

    Export `forkProcessWithUnmask` from `System.Posix.Process`

    This is a follow-up to 17192d89e6 which missed that export.

    Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>