As next step, all gPad-related functions will be removed completely

Only one method and TBaseMesh class are used from outside

All these objects has to be deleted at the end - only polyshape with
triangles will remain

Instead of using gPad and TvirtalPainter3D one can directly create shape
TBuffer3D and calculate CSG. On the long run this is a method, which
should be used in TGeoBoolNode classes.

Added GDML support for: opticalsurface, skinsurface, bordersurface, matrix, property, including test macro

The mechanism attempting to find v6 equivalent for names found
in v5 files (eg. adding missing namespaces) under some circunstances
(see ROOT-9784) would create class name with missing template parameter
(eg literally map<,RooExpensiveObjectCache::ExpensiveObject*>

This is a fix for commit c412ad28

since we now have a fwd declaration in RInterface.hxx

- IsImplicitMTEnabled
- EnableImplicitMT
- DisableImplicitMT

Instead of removing the *.pyc file in argparse2help.py,  we avoid to generate such files
by invoking argparse2help.py with option -B.

[RDF,PyROOT] Rename TTreeAsFlatMatrix header to PyROOTHelpers and change namespace from Detail to Internal

Needed for MSVC, since it does not understand -fvisibility=hidden.

Clang defines __GNUC__ then complains it doesn't know the
warning options from GCC since it doesn't know -Wpragmas
either:

core/clingutils/res/TClingUtils.h:28:32: warning:
 unknown warning group '-Wclass-memaccess', ignored [-Wunknown-warning-option]
 #pragma GCC diagnostic ignored "-Wclass-memaccess"

Also avoid warnings about deprecated register due to Qt4

If libPyROOT is loaded with gSystem->Load, the static
initialization block in TMemoryRegulator.cxx is executed and
ends up invoking PyCFunction_New, which causes a crash from
Python 3.7. The crash is due to Python not being initialized.
This also happens when using TPython from C++, since Python
has not	been initialized when TPython is used.

Note that when loading libPyROOT from ROOT.py, which is what
happens when someone uses PyROOT, the Python interpreter already
exists and is initialized, so invoking PyCFunction_New does not
crash.

This fix moves the creation of gObjectEraseCallback away from
the static block in TMemoryRegulator in order to prevent the
issue described above.

in order to verify that the same objects read from two different
TFiles pointing to the same physical file have different pointers.

This reverts commit 22c5dd19.
root.exe and hsimple do not need GeomPainter.

Now calling

  auto f1 = TFile::Open("hsimple.root");
  auto f2 = TFile::Open("hsimple.root");
  auto d = f2->GetDirectory("hsimple.root://);
  assert(d == f2);

return f2 rather than f1 (because it is first in the list of files)

Deprecate afdsmgrd bonjour castor geocad globus gviz hdfs krb5 ldap memstat odbc qt qtgsi rfio table:

This emits a warning when the module is enabled.
We have no tests for these modules, we expect no actual usage of them, and there are better alternatives.

The warning:

core/base/src/TSystem.cxx:1149:14: warning: ‘char* strncat(char*, const char*, size_t)’ accessing 1 byte at offsets 0 and [-2147483647, 2147483648] may overlap 1 byte at offset [0, 2147483649] [-Wrestrict]
       strncat(buff, c+1, n);
       ~~~~~~~^~~~~~~~~~~~~~

is wrong because gcc8 does not (can not) detect that the input is already trimmed to kBufSize [strlcat(inp, c, kBufSize);]
and that the buffer is also used in a segmented way (4 portion of kBufSize each).

Switch from strncat to strlcat to suppress the warning.
Add an assert expressing the known precondition.