* 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.

Use assert when detect keys duplication

Clear deistinguish batch and non-batch methods, return bool when
expected

1. use alias for timestamps
2. Define FindOrCreateConnection
3. Remove unused code

Only when multithreading is used, internal I/O locks should be used

One should use ROOT::EnableThreadSafety() call if canvas have to be used
in multithreaded environment

Support new RCanvas/WebWindow functionality
Improve PNG image generation for canvas with 2d/3d graphics

Use recursive, while can be locked many times in different places of
same thread

If same batch job reused second time, one should update drawing
correspondently

When many threads tries to stream same class for first time - it causes
I/O problem while many TClass and TStreamerInfo instances need to be
created. Probably global ROOT mutex has to be used.