firewall: rules.pl: Remove totally bloated debug mode.
firewall: rules.pl: Fix some coding style.
firewall: rules.pl: Introduce a more slink debugging mode.
firewall: rules.pl: Remove command line args parsing and rest from old debugging mode.
firewall: rules.pl: Remove $command and introduce $IPTABLES.
general-functions.pl: Fix wrong perl syntax.
firewall: rules.pl: Cleanup rule generation.

Various perl coding errors that have been suppressed by "no warnings uninitialized"
have been fixed and lots of helper variables have been introduced to make
it much more clearer what the code is actually doing.
firewall: rules.pl: Cleanup time constraints generation.
firewall: rules.pl: Refactored entire script.
firewall: Allow accessing port forwardings from internal networks.
firewall: Make OpenVPN access also possible when INPUT policy is REJECT.
firewall: Telnet uses TCP
firewall: Resurrect port forwardings with different external ports.
Merge branch 'next' of ssh://git.ipfire.org/pub/git/ipfire-2.x into next
firewall: rules.pl: Replace some hardcoded chain names.
firewall: rules.pl: Remove unused variable $time_constraints.
firewall: Add a trailing space to all log prefixes for better readability.