perl termination fixes: *) master exit hook is run before global pool cleanup, so call PERL_SYS_TERM() after perl_destruct()/perl_free(). This fixes the message panic: MUTEX_LOCK (22) [op.c:352] on some threaded perl builds *) call perl_destruct()/perl_free() before PERL_SYS_TERM() for non-mulitiplicity perl