Fix various differences for rhel5

[hunner]

iptables 1.3.5 ships on rhel 5 and is really old. It doesn't support --comment on ip6tables, doesn't support -m socket or --random, and the format of netmasks uses subnet mask format instead of CIDR.

[mrwacky42]

Heh, we have this workaround currently:

  case $::osfamily {
    'RedHat': {
      if $::lsbmajdistrelease >= 6 or $::operatingsystem == 'PSBM'{
        $firewall_supports_ipv6 = true
      }
      else {
        $firewall_supports_ipv6 = false
      }
    }