TraversalStrategy.isApplicable(Traversal root)

This is a non-breaking update to the TraversalStrategy API. There are currently 2 strategies that need to analyze the traversal from the root traversal to know if the strategy should be applied. The problem, strategies work on a per-traversal basis – not on the entire traversal as a whole. To make it more efficient for these global analysis traversal, we should have a boolean TraversalStrategy.isApplicable(Traversal root) which will run once and only run to determine if the strategy should be applied to all nested traversals.