added open graph post on linkedin

188) support open graph post to facebook.
     https://developers.facebook.com/docs/graph-api/reference/v2.2/user/feed
     extra information for link: picture, name, caption, description
     without picture attachment - something like this
     api_response = api_client.put_connections('me', 'feed',
                                               :message => message, :picture => g.open_graph_image, :name => g.open_graph_title, :description => g.open_graph_description,
                                               :link => 'http://localhost/da/gifts/p6m3e3xrypfpmfrkaytm2yEocUbBYU', :caption => SITE_URL)
     use description from gift?

190) add open graph list to linkedin.
     http://developer.linkedin.com/documents/share-api