refactor(Node): call 'start' callback before chain without waiting for chain sync

We were previously waiting until the chain was all the way synced, which can take a while.

Author: mappum

lib/node.js

@@ -46,13 +46,17 @@ var Node = module.exports = function (opts, cb) {
 util.inherits(Node, EventEmitter)
 
 Node.prototype.start = function (cb) {
+  var self = this
   cb = cb || function () {}
 
   this.peers.on('peerconnect', this._onPeerConnect.bind(this))
 
   async.parallel([
     this.peers.connect.bind(this.peers),
-    this.chain.sync.bind(this.chain)
+    function (cb) {
+      self.chain.on('syncing', function () { cb(null) })
+      self.chain.sync()
+    }
   ], cb)
 
   this.emit('ready')