Argparse

I added argparse so we can feed in login info from the CLI instead of hardcoding.  I also changed the log file name name to device.log where device is the IP or hostname we logged in to.

I don't see any way to contact you via github to ask permission to edit the repo so I forked it and edited mine (not knowing at the time that it was going to give me this merge/pull option).  

I added comments in the code but probably should have put some in README as well.