i* Synced with Seattle's r7319, typecast for RECV_BYTES.
* Removed Affix support on the control connection.
* Consequently changed callargs: You can now specify an override NAT_FORWARDER_KEY to announce (rather than an Affix stack). Handy for testing!
* Works with natpunchaffix@6f8608e3b12cf9fa28e93ee4c34225cd11c2f0e5.