Log Message:
Changes 1.8.20141022:
* Discard NAT-PMP packets coming from the WAN
* small modifications to compile with exotic C libraries
* add comments in miniupnpd.conf regarding security
* DeletePortMapping now checks for client IP in Securemode
* Various fixes :
    e->ipv6.flags |= IP6T_F_PROTO; (netfilter)
    fix natpmp.c byte order conversion
    add small delay before SSDP response to prevent flooding