Make TH1::Copy public , to be able to do deep copy of TH1 pointers without using TH1::Clone
Remove usage of TRef in HistFactory. It is not needed. Replace with a simple wrapped class to manage histogram pointer
(RooStats::HistFactory::HistRef)
This should fix a bug reported by Swagato
Fix also memory leaks created by cloning histograms in histooworkspace
Add a histfactory test from Christian (stresshistFactory ) in $ROOTSYS/test
Fix makefile test for stressHistFactory