added support for returning accuracy of ray intersections and other octree tests that can fail due to getting lock

For all the Octree methods that had an optional TryLock/Lock mode, this now also allows the caller to pass a pointer to a bool which will be filled in with the accuracy of the call. (false if the lock was not obtained).

I updated the voxel JS for rayIntersection() to use this parameter and include in the result whether or not the ray intersection was accurate.

I also added a new findRayIntersectionBlocking() which will force a lock and guarantee an accurate result.