ENH,DOC: argparse + sphinx-argparse

- [ ] **argparse**
  - https://docs.python.org/dev/library/argparse.html
  - https://docs.python.org/2/howto/argparse.html
  - https://docs.python.org/2/library/argparse.html#module-argparse
- [ ] **sphinx-argparse**
  - https://github.com/ribozz/sphinx-argparse
  - http://sphinx-argparse.readthedocs.org/en/latest/
