Remove argparse dependency?

[leeping]

I am not sure if we should change argparse to optparse for the following reasons.

• According to Python development, optparse is deprecated as of version 2.7 and might be removed at some point in the future.
• argparse is an installable package for version 2.6 and older.
• The script uses argparse-only features for a few things, e.g. the "ffxml" option takes a variable number of arguments. (i.e. nargs='+'

http://stackoverflow.com/questions/3217673/why-use-argparse-rather-than-optparse