[RC1] addServers works almost same as in Gearman PECL library.

Usecase from PHP PECL gearman extension

``` php
<?php

$worker= new GearmanWorker(); 
$worker->addServers("10.0.0.1,10.0.0.2:7003");

?>
```

In this library you can also pass an array. It is up to developer if he passes hosts with ports as string or as array.