v4.0-sl5: legacy SL5 release
Please use v4.0.1-sl5 instead, which fixes a bug that could cause crashes in some circumstances (#165)
This is the latest SL5 release, including everything that was developed so far in SL5.
To be used on top of CMSSW_6_1_1 (or any release with the same roofit and roostats versions) for SL5