Changes to ghc

Changes to ghc:
commit 26942dbf47dc6d1d076869b963de9501d27a040b
Author: Krzysztof Gogolewski <krz.gogolewski@gmail.com>
Date:   Sat Feb 1 14:03:34 2014 +0100

    Remove some references to deprecated -fglasgow-exts in user's guide