Use argparse instead of parsing arguments manually
Use argparse instead of parsing arguments manually

argparse is used, and the exit code 2 is aslo added, if there is
something wrong with the input.

Change-Id: I8ebc73934cd74306d11fadb3839bb562f95c455e
Closes-Bug: #1615966

openstack/dragonflow,openstack/dragonflow,openstack/dragonflow