Compares this node state against the given base state. Any differences are reported by calling the relevant added/changed/deleted methods of the given handler.
TODO: Define the behavior of this method with regards to iterability/existence of child nodes.
@param base base state
@param diff handler of node state differences
@return {@code true} if the full diff was performed, or{@code false} if it was aborted as requested by the handler(see the {@link NodeStateDiff} contract for more details)
@since 0ak 0.4, return value added in 0.7