comments, small fixes

lib/clouddns/client/domains.rb

@@ -83,23 +83,23 @@ def update_domain(domain)
 
     # Delete an existing domain. Returns an AsyncResponse instance
     #
-    # domain - CloudDns::Domain instance
+    # domain - CloudDns::Domain instance or domain ID
     #
     # @return [Hash]
     #
     def delete_domain(domain)
       options = {'deleteSubdomains' => true}
-      async_response(delete("/domains/#{domain.id}", options))    
+      async_response(delete("/domains/#{domain_id(domain)}", options))    
     end
 
     # Export domain contents
     #
-    # domain - CloudDns::Domain instance
+    # domain - CloudDns::Domain instance or domain ID
     #
     # @return [CloudDns::ExportRecord]
     #
     def export_domain(domain)
-      resp = get("/domains/#{domain.id}/export")
+      resp = get("/domains/#{domain_id(domain)}/export")
       data = async_response(resp)
       ExportRecord.new(data)
     end

lib/clouddns/domain.rb

@@ -86,6 +86,10 @@ def delete
       new? ? false : @client.delete_domain(self)
     end
 
+    # Export domain data
+    #
+    # @return [CloudDns::ExportRecord]
+    #
     def export
       @client.export_domain(self)
     end

lib/clouddns/record.rb

@@ -43,6 +43,7 @@ def initialize(client, data={})
         raise ArgumentError, "CloudDns::Client required!"
       end
 
+      # Check if we've got all the data
       raise InvalidRecord, "Record :name required!" if @name.empty?
       raise InvalidRecord, "Record :type required!" if @type.empty?
       raise InvalidRecord, "Record :data required!" if @data.empty?