Except for tests that mock internals of ExecutionPlanBuilder,  very simple queries can now be built end to end with the new query planner
Code style reformatting
Handles single nodes with labels now
Adds the culling plan generator
Adds ExpansionPlanGenerator.scala
Clean up PipePlanProducer.scala so it produces LeafPipes instead of StartPipes
The new query plans can now solve plans with relationships in them
In the middle of adding hash joins