daemon: improve local router public port managenent support using NAT-PMP
Issue generated from Tuleap's migration script. Originally submitted by: Guillaume Roguez (guillaume)
libupnp suffers of numerous issues with some routers (crash if IPv6, latency, fails to reallocat port, ...)
NAT-PMP is a small and effictient library that gives this port management on router.
This is used by many upstream FOSS projects.
The idea is to integrate this library, in parallele with libupnp (for autodiscovery).