cocked up half done test readability helper

will need to rejigger overall API to return dictionary of various
replacement values..  this will allow for future helpers that get the actual
URL from sites like tinyurl, etc
extended the UrlHelper so that it could return a dictionary with more
information (url, description, title).

Used that to add a ReadabilityUrlHelper that records the actual url
readability is targetting as opposed to their iframe nonsense thing

could certainly use some optimization