Add people equivalence
If no people are resolved, return 404 rather than internal server error
Maintain person lookup entry store when saving people
Update ids in CrewMembers when writing their Person
Merge branch 'mbst-4778-people-equivalence' into stage

* mbst-4778-people-equivalence:
  Maintain person lookup entry store when saving people
  If no people are resolved, return 404 rather than internal server error
  Add people equivalence

Conflicts:
	src/main/java/org/atlasapi/persistence/MongoContentPersistenceModule.java
Merge branch 'mbst-6047-people-ids' into stage

* mbst-6047-people-ids:
  Update ids in CrewMembers when writing their Person

Conflicts:
	src/main/java/org/atlasapi/persistence/content/mongo/MongoPersonStore.java
	src/test/java/org/atlasapi/persistence/content/mongo/MongoPersonStoreTest.java