Appenders is not properly closed upon destruction

Appenders doesn't seem to be properly closed. The LoggerAppenderSkeleton::finalize() is only used in __sleep() and __wakeup(), but the normal situation would at least be to close appenders upon __destruct() if not closed already. Because of this bug no footers are applied to the layout of an appender as well (like the HTML and XML layouts need to close their tags properly).