We've upgraded SilverStripe core to PHPUnit 4.x now, and the Functions.php has moved locations.
Since all custom contexts either use one of these contexts, or extend off SilverStripeContext,
we can be certain that the required assertions are automatically included for custom contexts,
no need to duplicate the require_once() calls.
Note that Behat 3.x suggests using static methods on a class, e.g. PHPUnit_Framework_Assert::assertSame (see http://docs.behat.org/en/master/quick_intro.html).
This seems quite verbose, and increases the upgrade burden on any project using Behat.
applyState() used to persist in memory, which could lead
to outdated state depending on execution flow between CLI
and web requests. Since state is now in a JSON object,
it also fixes the array access.
