Save on Document & ExtendedDocument crashed if bulk

- document#save expects to receive {"ok" => true} even with bulk mode
- ExtendedDocument#save_without_callbacks reverted to previous code
  (expecting result["ok"] as in create_without_callbacks)

lib/couchrest/more/extended_document.rb

@@ -238,7 +238,7 @@ module CouchRest
       set_unique_id if new? && self.respond_to?(:set_unique_id)
       result = database.save_doc(self, bulk)
       mark_as_saved 
-      true
+      result["ok"] == true
     end
     
     # Saves the document to the db using save. Raises an exception