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.

After the upgrade of CPyCppyy to v1.5.1, the pythonisations of cppyy
do not inject anymore the __iter__ method on TCollections. Before the
update, cppyy was injecting __iter__ on any class that had a `begin`
and an `end` methods, which is the case of TCollection.

Since now cppyy does not inject __iter__, we can inject it ourselves
in our TCollection pythonisation and the subclasses of TCollection
will keep that pythonisation.

Became unused after 89ea0e7b.

This reverts commit 29eab9dc.
The problems in LCG nighlies were not caused by this change.

Returning the default ::operator new(...) gets rid of the warnings
without side effects, since the call to Fatal() means the operator
new will exit without actually returning to the caller.

Fixes: ROOT-9908

Fixes: ROOT-9916

This reverts commit 330a82e3.
This commit possibly broke LCG nightlies due to external usage
of ROOT_GENERATE_DICTIONARY() macro. Reverting to test.

This leads to errors due to absolute paths if ROOT is already
installed in the configured prefix (e.g. /usr/local):

CMake Error at cmake/modules/RootNewMacros.cmake:288 (message):
  Header path
  '/usr/local/include/ROOT/RVirtualCanvasPainter.hxx'
   /usr/local/include/ROOT/RVirtualCanvasPainter.hxx
  is not relative!
Call Stack (most recent call first):
  cmake/modules/RootNewMacros.cmake:968 (ROOT_GENERATE_DICTIONARY)
  graf2d/gpadv7/CMakeLists.txt:6 (ROOT_STANDARD_LIBRARY_PACKAGE)

However, we only want this behavior for ROOT itself and not dependent
projects, which still use globbing in their build systems.

otherwise, at constrction time of TUrl, races take place setting the
fgSpecialProtocols variable.

this is done because strtok is not reentrant.

Update LZMA package hashes and version of packages