netio230a_ctrl CLI changes:

Cleaning up the code by:

* Using argparse instead of optparse
  Args' logic and types are now simplified.
* Porting it to work with Python 2.7 and 3.4
  (don't know about older versions)
* Structuring imports, global vars and the doc string
* Removing unnecessary comments
* Using print() as a function
* Using new try/except syntax