Fix duplicate article links being used as guid

For feeds that do not provide a guid for each article, the link is used as the guid. Unfortunately, some feeds have more than one article that has the same link. The articles with the duplicate link also have a different title and publication date. See https://developer.apple.com/news/rss/news.rss as an example with two articles in it both having a link of https://developer.apple.com/news/index.php?id=11032010b . 

This means that in the staged article update process, the two separate articles keep getting their crawl date/times updated as they have the same guid, but different publication dates. The side effect is these two articles are continually being displayed at the top of the list of user articles as they keep having new crawl date/times being set everytime the crawler process is run.

As a result an additional item needs to be included to filter what articles should have the crawl date/time set. This branch contains a change that filters articles to that need their crawl date/times to be set that have the same guid AND article title. This fixes this problem in the rare cases that it occurs.