small fixes to Vdc to allow vdc.servers to work

lib/fog/terremark/models/shared/server.rb

@@ -10,6 +10,8 @@ module Fog
 
         attribute :name
         attribute :status
+        attribute :OperatingSystem
+        attribute :VirtualHardware
 
         def destroy
           requires :id

lib/fog/terremark/models/shared/task.rb

@@ -13,8 +13,8 @@ module Fog
         attribute :result,      'Result'
         attribute :start_time,  'startTime'
         attribute :status
-        attribute :link         'Link'
-        attribute :error        'Error'
+        attribute :link,         'Link'
+        attribute :error,        'Error'
 
         def initialize(attributes = {})
           new_owner  = attributes.delete('Owner')

lib/fog/terremark/models/shared/vdc.rb

@@ -18,6 +18,10 @@ module Fog
           connection.addresses(:vdc_id => @id)
         end
 
+        def servers
+          connection.servers(:vdc_id => @id)
+        end
+
         private
 
         def href=(new_href)