Just return the granularity discovered to be empty from findPath and
provide it to requestChangesets. This is very sub-optimal, as it will
almost always result in granularity==1.
There are still some bugs in the traversal algorithm, as well
as bugs being triggered in the server. Also, for some reason it looks
like there is a problem with the attribute pool not containing certain
elements.
findPath works. transition requests changesets from server. processing
of changesets works correctly.
Only need to manage the async-ifying of transition, which is currently
written as a while loop, (with a short-circuit break for debugging).