refactored screen scraping into object.  updated the controllers and models accordingly

As we talked about on the phone, I moved all the logic from ApplicationController#display_url into a separate object.  That new class is defined here:  lib/screen_scraper.rb

The ScreenScraper object stores all the values in and prints them out in the view.  I had to refactor some of the controllers also to make everything work.  However, even at this point, the controllers are not handling errors gracefully.  We can discuss this further if you want.  I am also going to leave some code-line-level notes on the pull requests explaining some of the work.

If this was my own project, I would *definitely* write tests for the ScreenScraper object.  I like to use the rSpec library to handle testing.  I'd be happy to get you started, however, that is a fairly big topic, so I won't go into it here.

I can also help you merge this pull request into your code if everything makes sense.  If you want to test this out locally, you can also just pull down my `refactor_screen_scraping` branch and run that locally to test it out.  I am also happy to help you with that.