Remove --disable-quiet and quiet mode, default to a sane behavior

This patch is a follow-up to 1f1c2e0 which introduced the new semantics
for the very confusing quiet and silent modes.

The initial idea was to loosely follow the kernel cmdline 'quiet' option
and as a working concept this was good.  The resulting code, however,
became unnecessarily complex and the configure options impossible to
explain.

With this patch the quiet mode, and thus the --disable-quiet configure
option, is removed.  Finit now defaults to a sane behavior: services are
shown only at startup.   The --enable-silent option works like it did
before, silencing everything.

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

src/finit.c

@@ -202,7 +202,7 @@ static void emergency_shell(void)
 	if (pid) {
 		waitpid(pid, NULL, 0);
 		fprintf(stderr, "\n=> Embarrassingly, Finit has crashed.  Check /dev/kmsg for details.\n");
-		fprintf(stderr, "=> For more, remove 'quiet' and add '--debug' to the kernel command line.\n\n");
+		fprintf(stderr,   "=> To debug, add '--debug' to the kernel command line.\n\n");
 
 		/*
 		 * Become session leader and set controlling TTY