Add Unix socket example.

examples/unix_socket.js

@@ -0,0 +1,15 @@
+var redis = require("redis"),
+    client = redis.createClient("/tmp/redis.sock");
+
+client.on("connect", function () {
+    console.log("Got Unix socket connection.")
+});
+
+client.on("error", function (err) {
+    console.log(err.message);
+});
+
+client.info(function (err, reply) {
+    console.log(reply.toString());
+    client.quit();
+});