Fix #45: add support for rlimit per service/run/task/inetd/tty

This patch extends the existing rlimit implementation to support setting
limits per service, run/task, inetd, and tty.

Use rlimit in /etc/finit.conf to change the global setting, which is
then inherited to each /etc/finit.d/*.conf.  For each .conf file the
rlimit is reinitialized to the global finit.conf settings.

Also, add `unlimited` keyword, to replace the now deprecated `infinity`
keyword.  The latter is however kept, for compatibility with previous
releases, for the foreseeable future.

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

src/finit.c

@@ -357,7 +357,7 @@ int main(int argc, char* argv[])
 
 			/* Register udevd as a monitored service, started much later */
 			snprintf(cmd, sizeof(cmd), "[12345] %s -- Device event manager daemon", path);
-			if (service_register(SVC_TYPE_SERVICE, cmd, NULL)) {
+			if (service_register(SVC_TYPE_SERVICE, cmd, global_rlimit, NULL)) {
 				_pe("Failed registering %s", path);
 				udev = 0;
 			}