Add service logging

Adds an extra 'log' parameter to services that routes STDOUT and STDERR to syslog.
Uses a PTY rather than a pipe, as this prevents log messages hanging around in a buffer indefinitely.

svc.h

@@ -101,6 +101,8 @@ typedef struct svc {
 	inetd_t        inetd;
 	int            stdin;
 
+	int log;
+
 	/* Identity */
 	char	       username[MAX_USER_LEN];
 	char	       group[MAX_USER_LEN];