retrieve region-specific and category-specific standardfeeds

Use region-specific and category-specific filters for the standardfeeds
https://developers.google.com/youtube/2.0/developers_guide_protocol_video_feeds

eg:
YouTubeIt::Request::StandardSearch.new(:top_rated, :offset => 5, :max_results => 10, :time => :today, :region => "RU", :category => "News")