Added better support for complex chrome switches (THUCYDIDES-226)

You can now pass chrome switches containing spaces, commas etc, e.g.
--user-agent=Mozilla/5.0 (Linux; Android 4.0.4; Galaxy Nexus Build/IMM76B)AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.133 MobileSafari/535.19
Updated version
Added the takesScreenshots() method to the DriverSource interface (THUCYDIDES-215)

This allows provided drivers to specify if they support screenshots.
Session data is cleared between unit tests

Session data, in Thucydides.getCurrentSession(), is now cleared between each test. This data can be deactivated by setting the 'thucydides.maintain.session' property to true.
Wait for timeout for PageObjects using the webdriver.timeouts.implicitlywait system property (THUCYDIDES-225)

Honor the webdriver.timeouts.implicitlywait system property when configuring the timeout value of a PageObject.