Cleaned up the Downloader handleRedirect() function.
Changed inheritance code to use util.inherits().
Changed PageScraper url test to use Array.filter().
Simplified PageScraper next page string search.

Since we're looking for a simple string within another string there
really is no reason to be using a RegExp here.
Saved resPath to a variable in PageScraper.
Changed arg validation errors to use exit code 1.