Updates to MCMCInterval, MCMCIntervalPlot, RooStatsUtils and SequentialProposal. StandardBayesianMCMCDemo.C is also updated.


git-svn-id: https://root.cern.ch/svn/root/branches/dev/roostats@48872 27541ba8-7e3a-0410-8455-c3a389f83636
Adding py folder to tutorials/roostats/. Adding basic functions for python scripts with PyROOTUtils.py and helperStyle.py. Adding SequentialProposalDemo.py.


git-svn-id: https://root.cern.ch/svn/root/branches/dev/roostats@48873 27541ba8-7e3a-0410-8455-c3a389f83636