Add NAt support for HTTP server

lib/server.js

@@ -10,13 +10,15 @@ var url = require('url')
 
 function Server (torrent, opts) {
   var server = http.createServer(opts)
+  var natTraversal = require('./nat-traversal')
 
   var sockets = []
   var pendingReady = []
   var closed = false
 
   server.on('connection', onConnection)
   server.on('request', onRequest)
+  server.on('listening', onListening)
 
   var _close = server.close
   server.close = function (cb) {
@@ -36,6 +38,10 @@ function Server (torrent, opts) {
       socket.destroy()
     })
 
+    if (server.address()) {
+      natTraversal.portUnMapping(server.address().port)
+    }
+
     // Only call `server.close` if user has not called it already
     if (closed) process.nextTick(cb)
     else server.close(cb)
@@ -134,5 +140,9 @@ function Server (torrent, opts) {
     }
   }
 
+  function onListening () {
+    natTraversal.portMapping(server.address().port)
+  }
+
   return server
 }