Internal rename only
Moved tests to corresponding packages as well

Forgot earlier when separated BFS and DFS
Internal rename only
Organized imports
Implemented DFS without history

No keeping track of history means near-constant memory consumption,
which was over the roof for the existing implementations. Will be slower
but it will actually be able to finish. Also, should be pretty easy to
save the search state ... a feature to be added later perhaps
Improved search monitor output
Children are now ordered

Rules now map a state to an ordered sequence of states for
reproducibility
Added search monitor for BFS
Refactored BFS to prepare for low-memory processing

Looping over visited states collection, processing states one by one.
Once visited states collection is on disk this will require very little
memory.
Moved case class to top level so it's serializable

Required for db storage
Added "depth finished" logging for BFS monitor