Load the next favicon if a favicon is invalid
Iterate through multiple favicons and use the first that actually loads
- Add a homePageURL property to SingleFaviconDownloader that notification observers can use.
- Only add a URL to the favicon cache when we're sure it's valid.
Post notification even if the icon failed to load
Update RSParser
Remove single-favicon helper methods
Only load the next favicon if the current load failed
Update RSParser
Make sure to try the default favicon.ico
RSParser test fix update
Update RSParser
