ability to use a socket factory rather always use Socket()

Author: erh

src/main/com/mongodb/DBPort.java

@@ -199,7 +199,7 @@ boolean _open()
             IOException lastError = null;
 
             try {
-                _socket = new Socket();
+                _socket = _options.socketFactory.createSocket();
                 _socket.connect( _addr , _options.connectTimeout );
 
                 _socket.setTcpNoDelay( ! USE_NAGLE );

src/main/com/mongodb/MongoOptions.java

@@ -18,6 +18,7 @@
 
 package com.mongodb;
 
+import javax.net.SocketFactory;
 
 /**
  * Various settings for the driver
@@ -41,7 +42,9 @@ public void reset(){
         w = 0;
         wtimeout = 0;
         fsync = false;
+        j = false;
         dbDecoderFactory = DefaultDBDecoder.FACTORY;
+        socketFactory = SocketFactory.getDefault();
     }
 
     /**
@@ -166,6 +169,12 @@ else if (safe)
      */
     public boolean j;
 
+    /**
+     * sets the socket factory for creating sockets to mongod
+     * Default is SocketFactory.getDefault()
+     */
+    public SocketFactory socketFactory;
+
     public String toString(){
         StringBuilder buf = new StringBuilder();
         buf.append( "description=" ).append( description ).append( ", " );