This contracts release adds an optional DA Challenge contract for use with OP Plasma. If usePlasma is set to true in the deploy config, then the OP Plasma feature will be enabled.

The challenge DA contract is used to ensure that data posted as part of OP Plasma is made available. There are four deploy config parameters that must be set when using this feature: daChallengeWindow, daResolveWindow, daBondSize, daResolverRefundPercentage