fastd

* Very small binary (about 100KB on OpenWRT in the default configuration, including all dependencies besides libc)
* Exchangable crypto methods
* Transport over UDP for simple usage behind NAT
* Can run in 1:1 and 1:n scenarios
* There are no server and client roles defined by the protocol, this is just defined by the usage.
* Only one instance of the daemon is needed on each host to create a full mesh
* If no full mesh is established, a routing protocol is necessary to enable hosts that are not connected directly to reach each other