Better argument parsing

ROOT’s binaries understand a mixture of short and long arguments. The parsing is done in C++, with ad hoc C++ code. We would like to switch to a C++ command line argument library. This would imply implementing ROOT’s options (e.g. in TApplication.cxx and rootcling_impl.cxx) using that library.

Expected Results

• ROOT’s command line arguments are parsed with a C++ library; we can combine arguments: root -lbq tutorials/hsimple.C

Requirements

Basic C++ knowledge; there is nothing ROOT specific.