bump versions to 0.9.1-SNAPSHOT since we're refining the performance of existing features. Refine performance of things that need to check whether a path exists within the current set of roots and current filter...things like containsGraph() and getProjectCycles. Some of this involved batching one large call to getPaths and some involves caching the list of projects in the current graph. We could probably benefit from further refinement, but this is a start.
Deal with concurrent modification of cache entries, and key the caches to GraphView instances...allowing them to expire when the object it GCed