.conf: don't rely on mtime to determine if service needs reloading

Until now Finit has used mtime to determine if a file has been changed,
or simply touched to request reload, when `initctl reload` is called.
Using mtime for this purpose is a monumentally bad idea since time can
be changed at any point: a user may adjust the time, NTP continously
tunes the clock, and time stamps are stored as the walltime.  So if we
compare timestamps against the last time we (booted or) did reload, we
would miss .conf file changes.

This patch replaces the mtime mistake with an inotify watcher for the
following files: /etc/finit.d/*.conf, /etc/finit.d/available/*.conf,
and /etc/finit.conf.  All file changes between (bootstraps and) calls
to `initctl reload` are tracked, like the mtime backend it replaces.

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

src/tty.h

@@ -54,7 +54,6 @@ typedef struct tty_node {
 	finit_tty_t data;
 
 	/* XXX: Yes, TTYs should be refactored into a separate SVC type. */
-	struct timeval mtime;          /* Modification time for .conf from /etc/finit.d/ */
 	int            dirty;	       /* Set if old mtime != new mtime  => reloaded,
 					* or -1 when marked for removal */
 } tty_node_t;
@@ -62,10 +61,9 @@ typedef struct tty_node {
 //extern LIST_HEAD(, tty_node) tty_list;
 
 void	    tty_mark	    (void);
-void	    tty_check	    (tty_node_t *tty, struct timeval *mtime);
 void	    tty_sweep	    (void);
 
-int	    tty_register    (char *line, struct rlimit rlimit[], struct timeval *mtime);
+int	    tty_register    (char *line, struct rlimit rlimit[], char *file);
 int	    tty_unregister  (tty_node_t *tty);
 
 tty_node_t *tty_find	    (char *dev);