On reload/restart we must wait for services to stop first

This patch adds support for declaring *why* a service is being stopped
or reloaded.  This is later used when all stopped services have been
collected by the `service_monitor()` to issue start or postponed SIGHUP.

As an added benefit we can now also see why a service is not running.
If it has been paused by a user, halted when moving to another runlevel,
waiting for a condition (event), or similar.

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

service.h

@@ -33,7 +33,7 @@ void      service_unregister     (svc_t *svc);
 svc_cmd_t service_enabled	 (svc_t *svc, int event, void *arg);
 
 int	  service_start	         (svc_t *svc);
-int	  service_stop	         (svc_t *svc);
+int	  service_stop	         (svc_t *svc, int state);
 void      service_start_dynamic  (void);
 void      service_stop_dynamic   (void);
 int       service_restart        (svc_t *svc);