fix http://root.cern.ch/phpBB3/viewtopic.php?f=3&t=17502
Protect in case of only 1 point. Fix ROOT-5397
Fix a bug (ROOT-5200) in computing the bin errors in TH2::Smooth
Apply fixes for ROOT-5058

Add SetBins method in TEfficiency
Add new methods CreateGraph and CreateHistogram which create the histograms used to paint the class. They can now be called without drawing it.
 o) move gROOTModule into PyROOT namespace
 o) add special "gNullPtrObject" as identifiable NULL (nullptr)
meant '||' instead of '&&' ...
Adding copy constructors to build models using python more robustly.
bugfixes. Fix HF for models without any nuisance parameters.
Bugfix copy constructor for non-counting models.
When checking consistency of histogram (e.g. in TH1::Add)  check only the relevant axis (e.g ignore y and z axis for 1D histos)/
this fix ROOT-5249