Reverse method on event readers.

[ploeh]

Both FifoEvents<T> and LifoEvents<T> should have a Reverse method.

• FifoEvents<T>.Reverse should return the equivalent LifoEvents<T> instance.
• LifoEvents<T>.Reverse should return the equivalent FifoEvents<T> instance.

[ploeh]

Resolved in e6597c55c4296b749c0ee901c86e63b7c8de2252.