Fix : Some icons weren't fetched

I realized that the icons weren't fetched for quite a lot of feeds I read. I added a few lines of codes to correct that. I didn't add a lot of stuff :
 - I added a search pattern for the icon link : `<link rel="icon" ... />`
 - I added a slash between the link and the favicon path (before that, if the link was `http://www.domain.tld/dir` and the favicon path was `favicon.ico`, the resulting icon url would be `http://www.domain.tld/dirfavicon.ico`)