Add basic support for runlevels and bugfix FIFO I/O plugins

Like most other init implementations do, when entering runlevel 1, finit
creates the file /etc/nologin to prevent users from logging in during
single-user mode, this file is then removed upon leaving runlevel 1.

Also, bugfix how FIFO I/O plugins are handled in finit.  A FIFO will
need to be reopened by the server side when the client closes the pipe.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

svc.h

@@ -50,6 +50,7 @@ typedef enum {
 typedef struct svc {
 	pid_t	       pid;
 	int	       reload;
+	int            runlevels;
 	unsigned int   stat_restart_counter; /* Incremented for each restart by service monitor. */
 	char	       cmd[MAX_ARG_LEN];
 	char	       args[MAX_NUM_SVC_ARGS][MAX_ARG_LEN];
@@ -87,6 +88,7 @@ static inline svc_t *finit_svc_connect(void)
 svc_t    *svc_new           (void);
 svc_t    *svc_find          (char *name);
 svc_t    *svc_iterator      (int restart);
+void      svc_runlevel      (int newlevel);
 
 int       svc_register      (char *line, char *username);
 int       svc_id_by_name    (char *name);