Support for shortcut icon link tag

[jleclanche]

https://github.com/mjibson/goread/blob/master/goapp/utils.go#L391 seems to only check for /favicon.ico. Several websites don't provide that, and instead provide a shortcut icon link tag. Example: http://www.questionablecontent.net/

Half my feeds are missing their icons because of it :)

[xosevp]

Maybe some code of these proyects can help:

• getFavicon http://g.etfv.co/ code: http://github.com/potatolondon/getfavicon
• commafeed implementation(java): http://github.com/Athou/commafeed/blob/master/src/main/java/com/commafeed/backend/feeds/FaviconFetcher.java