app.config ConfigurationManager

http://msdn.microsoft.com/ru-ru/library/system.configuration.configurationmanager(v=vs.110).aspx

http://stackoverflow.com/questions/19232695/how-to-use-configurationmanager

http://msdn.microsoft.com/ru-ru/library/system.configuration.configurationmanager.appsettings(v=vs.110).aspx

http://stackoverflow.com/questions/20195198/how-to-use-configurationmanager-appsettings-with-a-custom-section

http://stackoverflow.com/questions/10766654/appsettings-get-value-from-config-file