Added CLI interface and did a little clean up.

[lwahlmeier]

Added CLI ability because I wanted to run this from cron w/o using a web server. I also cleaned up some of the methods that where taking parameters they already had access to through the classes _config variable.

[Stanback]

Thanks for the pull request - this looks good. I'll test it over the weekend and merge.

[snicker]

This is working perfectly for me. thanks @lwahlmeier, makes the demise of my old dyndns account less of a bummer