Add support for a deny filter syntax to inetd services

This patch changes the syntax for custom inetd services and adds support
for deny filters.  The new syntax is:

    inetd service/proto[@iface,!iface,...] </path/to/cmd | internal[.service]>

This means the second column now defines what@from and the third to/what
process.  For internal services on a custom port the internal.service
syntax must be specified, so Finit can properly bind the inetd service
to the correct plugin.  Here follows a few examples:

    inetd time/udp                    wait [2345] internal                -- UNIX rdate service
    inetd time/tcp                  nowait [2345] internal                -- UNIX rdate service
    inetd 3737/tcp                  nowait [2345] internal.time           -- UNIX rdate service
    inetd telnet/tcp@*,!eth1,!eth0, nowait [2345] /sbin/telnetd -i -F     -- Telnet service
    inetd 2323/tcp@eth1,eth2,eth0   nowait [2345] /sbin/telnetd -i -F     -- Telnet service
    inetd 222/tcp@eth0              nowait [2345] /sbin/dropbear -i -R -F -- SSH service
    inetd ssh/tcp@*,!eth0           nowait [2345] /sbin/dropbear -i -R -F -- SSH service

Access to telnet on port `2323` is only possible from interfaces `eth0`,
`eth1` and `eth2`.  The standard telnet port (`23`) is available from
all other interfaces, but also `eth2`.  The `*` notation used in the ssh
stanza means *any* interface, however, here `eth0` is not allowed.

NOTE: This patch breaks syntax compatibility with Finit v1.12!

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

initctl.c

@@ -198,7 +198,7 @@ static int usage(int rc)
 		"Commands:\n"
 		"        debug           Toggle Finit debug\n"
 		"        reload          Reload *.conf in /etc/finit.d/\n"
-		"        runlevel <1-6>  Set new runlevel\n"
+		"        runlevel <0-9>  Change runlevel: 0 halt, 6 reboot\n"
 		"        status          Show status of services\n"
 		"        start   <JOB#>  Start stopped service\n"
 		"        stop    <JOB#>  Stop running service\n"