

- catch all exception by default and try to make a nice error message.
- have a [--debug|-d] and a [--verbose|-v] for all application by default.
  - debug would allow display of full traceback and set the errorlevel to debug
    - when catching an exception on NON debug mode, perhaps suggest to retry with --debug
  - verbose would allow display of information log

- for advanced usage, we could have a class descriptor for having
  argument validation or transformation for each arguments.

- the link between command line argument and config file should also
  be straightforward by default and configurable if wanted.
