Add links to Opengroup's latest POSIX.1-2008 spec

System/Posix.hs

@@ -10,7 +10,7 @@
 -- Stability   :  provisional
 -- Portability :  non-portable (requires POSIX)
 --
--- POSIX support
+-- <http://pubs.opengroup.org/onlinepubs/9699919799/ POSIX.1-2008> support
 --
 -----------------------------------------------------------------------------
 

System/Posix/ByteString.hs

@@ -10,7 +10,8 @@
 -- Stability   :  provisional
 -- Portability :  non-portable (requires POSIX)
 --
--- POSIX support with ByteString file paths and environment strings.
+-- <http://pubs.opengroup.org/onlinepubs/9699919799/ POSIX.1-2008>
+-- 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

unix.cabal

@@ -13,9 +13,10 @@ cabal-version:  >= 1.10
 tested-with:    GHC>=7.4.1
 description:
     This package gives you access to the set of operating system
-    services standardised by POSIX 1003.1b (or the IEEE Portable
-    Operating System Interface for Computing Environments -
-    IEEE Std. 1003.1).
+    services standardised by
+    <http://pubs.opengroup.org/onlinepubs/9699919799/ POSIX.1-2008>
+    (or the IEEE Portable Operating System Interface for Computing
+    Environments - IEEE Std. 1003.1).
     .
     The package is not supported under Windows.