Backport to slc5 changes which are there in slc6.
Merge pull request #754 from ktf/align-slc5-to-slc6

Align slc5 to slc6. This minimises changes to only gcc and the big FastSim datafiles.
Merge remote branch 'origin/IB/CMSSW_6_2_X/stable' into IB/CMSSW_7_0_X/stable