add support for unix domain sockets

[tantra35]

this is very useful for local fluentd, and remote aggregators

[tantra35]

For myself i use follow patch:

From 17be42a38e8518d7e44698b9cc4692808b8026e0 Mon Sep 17 00:00:00 2001
From: tantra35 <ruslan.usifov@gmail.com>
Date: Fri, 18 Sep 2015 17:54:16 +0300
Subject: [PATCH] Revert "add suport for unix domain sockets"

This reverts commit ea1bc845f652b1fd04d019a1d559c9ee9ebfe368.

add suport for unix domain sockets
---
 lib/sender.js | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/lib/sender.js b/lib/sender.js
index e2b2fc6..2cad841 100644
--- a/lib/sender.js
+++ b/lib/sender.js
@@ -8,7 +8,7 @@ function FluentSender(tag, options){
   options = options || {};
   this.tag = tag;
   this.host = options.host || 'localhost';
-  this.port = options.port || 24224;
+  this.port = options.port || null;
   this.timeout = options.timeout || 3.0;
   this.verbose = this.verbose || false;
   this._timeResolution = options.milliseconds ? 1 : 1000;
@@ -41,8 +41,11 @@ FluentSender.prototype.emit = function(/*[label] <data>, [timestamp], [callback]

   self._sendQueue.push(item);
   self._sendQueueTail++;
-  self._connect(function(){
-    self._flushSendQueue();
+  self._connect(function(err){
+    if(!err)
+    {
+      self._flushSendQueue();
+    };
   });
 };

@@ -102,12 +105,23 @@ FluentSender.prototype._connect = function(callback){
       if( self._socket ){
         self._socket.destroy();
         self._socket = null;
-        self._eventEmitter.emit('error', err);
+        callback(err);
+        //self._eventEmitter.emit('error', err);
       }
     });
-    self._socket.connect(self.port, self.host, function(){
-      callback();
-    });
+
+    if(self.port)
+    {
+      self._socket.connect(self.port, self.host, function(){
+        callback();
+      });
+    }
+    else
+    {
+      self._socket.connect(self.host, function(){
+        callback();
+      });
+    }
   }else{
     if( !self._socket.writable ){
       self._socket.destroy();
-- 
1.9.5.msysgit.0