Fields accessed by After hooks are null when using Spring or Guice

```
public class SomeHooks {

   private WebDriver driver;

    @Before
    public void startBrowser() {
        driver = new FirefoxDriver();
    }

    @After
    public void quitBrowser() {
        driver.quit();
    }
}
```

When using Spring or Guice (It does not affect picocontainer) the "driver" field will be null when accessed by the "quitBrowser" method executed as the After hook.
