Added in the ability for the Selenium 2 driver to get the window names of open windows. Related directly to: https://github.com/Behat/Mink/pull/341
Changed $this->session to $this->getSession().
Added in a new test to make sure that functionally the getWindowName functions work.
Updated some documentation.
Removed a duplicate test.
Adding a check for the new methods in the session object before trying to actually use it.
Removed unneeded return calls.
Merge pull request #55 from pthurmond/master

Gave Selenium 2 the ability to retrieve current open window names.