- this should address the ROOT-9681 JIRA item

This causes problems both in depedency generation, since clang ignores
headers marked as system, and due to the order in which headers are
processed (build directory is marked as system when TBB is builtin).

Updating comment about bug in ccache 3.1.x used together with clang (https://bugzilla.samba.org/show_bug.cgi?id=8118).
In commit was added the detection of version of ccache and extra check to apply flag -Qunused-argument for ccache version less then 3.2.0.

the tag called "E" was looked for but its name tested against the
string "N"

as well as the old tdfentry_ and tdfslot_. The tdf* columns
became aliases to the rdf ones.

when looking for enumerators.

efficiently and not variables.

Only connect/disconnect TGHtmlBrowser signals when it is present

This reverts commit dc825fc4.

* Centralise the generation of help for root command

Add argparse2help.py, add root-argparse.py, delete the old help of root, add the cmake commands needed to generate the header containing the command line options help and to generate manual page for the root command.

The python file argparse2help.py can be called with the root-argparse.py and the output name as arguments. This call will generate the header file if the output has an extension ".h" and will generate the manual page if the extension is ".1"

* Centralise the generation of help for the rest of the commands

Add cmake changes to generate headers and manual pages for rootcling hadd and hist2workspace
Delete old man pages of hadd and hist2workspace
Add commented out generation of man pages for python commands, we need to add a dependency before uncommenting them out
Add hadd rootcling hist2workspace argparse modules

* make the path compatible with windows

* review modifications

* add dependency on the input and the generation script of man pages

* remove installation of headers

* Update CMakeLists.txt

It makes no sense to generates man pages on Windows. Windows does not have the `man` command.

* Update argparse2help.py

* Update argparse2help.py

* Update argparse2help.py

* Update hadd.cxx

haddCommandLineOptionsHelp.h was not included for windows

* Update root-argparse.py

add the option --version

* Update argparse2help.py

simplified version (Thanks Bertrand !)

Should solve different compilation warnings.
Use directly version from head - not waiting for next releasy which
typically happens once a year.

If a TTree contained
1. branch "v" with a leaf "a", created with t.Branch("v", &a, "a/I")
2. a branch "w" containing a split struct that has a datamember "v" with a datamember "a"

constructing TTreeReaderValue<int>(r, "v.a") attached the reader to "w.v.a" instead of "v.a".
In this scenario there wad no way to access "v.a", because constructing TTreeReaderValue<int>(r, "v")
attached to "w.v" (and anyway, if it attached to the top level branch "v", it would have
yielded the following error message:

Error in <TTreeReaderValueBase::GetBranchDataType()>: The branch v was created using a leaf list and cannot be represented as a C++ type. Please access one of its siblings using a TTreeReaderArray:
Error in <TTreeReaderValueBase::GetBranchDataType()>:    v.a

This behaviour was due to the fact that TTree::GetBranch identified branch 2 and this had priority
wrt the search of branch elements the names of which contained a "dot".
This change reverts the priority order.