rpc: ensure shutdown. see #188.

lib/http/rpc.js

@@ -195,10 +195,22 @@ RPC.prototype.help = co(function* _help(args, help) {
 });
 
 RPC.prototype.stop = co(function* stop(args, help) {
+  var self = this;
+
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'stop');
 
-  this.node.close();
+  co(function* () {
+    try {
+      yield self.node.close();
+    } catch (e) {
+      if (process.exit)
+        process.exit(1);
+      return;
+    }
+    if (process.exit)
+      process.exit(0);
+  })();
 
   return 'Stopping.';
 });

lib/workers/workerpool.js

@@ -537,6 +537,7 @@ Worker.prototype._initChildProcess = function _initChildProcess() {
   var options = { stdio: 'pipe', env: env };
 
   this.child = cp.spawn(file, argv, options);
+  this.child.unref();
 
   this.child.on('error', function(err) {
     self.emit('error', err);