Not expose ROOT/RConfig.h to rootcling, but to add the header to
ROOT_Config pcm.

Use for bin edge comparisons an epsilon abs value that is computed as a fraction of bin width. This would give a more robust comparison test.
This should fix what has been shown in ROOT-7752

Looks like only TGeoCone was ignoring name.
Fixes error described in https://root-forum.cern.ch/t/32493

Functions that are outdated, but will not be removed, can be flagged with `R__SUGGEST_ALTERNATIVE`, a macro expanding to ROOT's `_R__DEPRECATED_LATER`. This can be used to point users to the recommended interfaces.

Flagging a function like this:
TIterator* createIterator() const
R__SUGGEST_ALTERNATIVE("begin(), end() and range-based for loops are faster.") {
   ...
}

and defining `R__SUGGEST_NEW_INTERFACE` in a translation unit will trigger a warning such as:
RooChebychev.cxx:66:34: warning: 'createIterator' is deprecated: There is a superior alternative: begin(), end() and range-based for loops are faster. [-Wdeprecated-declarations]
  TIterator* coefIter = coefList.createIterator();

IMPORTANT:
Theoretically, the macro could be used for classes: Don't!
This will trigger warnings for all uses of the class in the interfaces of ROOT.

* Make histfactory Samples copy-assignable.
Rootbench depends on copy assignment for the Sample class. After implementing move semantics to speed up hist2workspace, the copy assignment had been implicitly deleted. This was fixed, and a gtest has been added.
* Further, HistRef, a member of Sample, is now movable, and the histograms given back by Sample are now const TH1* instead of TH1*.

* Temporaries in python: In the RooFit python tutorials, C++ objects save pointers to objects held by python. When these are temporaries, this leads to crashes. Naming the temporaries works around this problem.
* rf204a: Add a new tutorial that demonstrates using extended pdfs when fitting in multiple ranges.

Before RegisterModule was assuming that "modulename" starts from "lib",
which is not the case for CMSSW where the "modulename" is
"SimDataFormatsValidationFormats_xr" for example.

hist2workspace reads histograms from multiple files, which often contain numerous folders with a lot of histograms.
It therefore needlessly suffers from TList::RecursiveRemove slowdowns, although almost all
histograms and files are read only. Implementing the memory management for histograms without ROOT's TList, and implementing move semantics with better const correctness leads to a speed up of a factor 10 for a large ATLAS-style Higgs workspace with 28 channels and about 150 systematic uncertainties.

Such operation causes a double delete attempt: one from gDirectory,
one from the Python proxy of the workspace.

The RooMinimizer does not allow to change the number of points on a likelihood contour.
By promoting this parameter to a default argument, this is now accessible to the user.
Doxygen was updated accordingly.

The analytical integral of RooGaussian was using erf() to compute the
integrals. Starting from x>5, this always yields 1 because of limited
precision.
Now, erfc() is used, which is much more accurate in the upper tail.
To retain the same precision in the low tails, all ranges are mapped
on the upper tail of the Gaussian before calling erfc.

in Defines and Filters.
When dealing with very large computation graphs with many Define/Filter
transformations defined with jitted strings, the time for matching
column names to strings was non negligible.

The previous mechanism to discover the columns present in the strings
to be jitted was based on regular expressions. The new approach is based
on a lexer, lexertk. The idea is to extract identifiers from
the string and then compare them with the column names available
in the DF.

Otherwise, cppyy will try to generate the PCH itself and we will
get a warning.

In macOS, SIP can prevent the setting of DYLD_LIBRARY_PATH from
having any effect in the Python process. In that scenario,
we need a fallback mechanism for cppyy to find libcppyy_backend
and the libraries it depends on.

This commit sets CPPYY_BACKEND_LIBRARY, which will be used by
cppyy to dlopen libcppyy_backend, in absence of LD_LIBRARY_PATH
and DYLD_LIBRARY_PATH.

The new interface in Converters deals with multi-dimensional arrays.