Add support for Yahoo Search subdomains

[moshekaplan]

Description Yahoo uses the following subdomains for different types of search:

• Web Search = "search.yahoo.com"
• Image Search = "images.search.yahoo.com"
• Video Search = "video.search.yahoo.com"
• News Search = "news.search.yahoo.com"

What is the best way to add these in at the top-layer?