Pulled serialization out of HomeInventoryTracker.
Created a PersistentStorageManager interface and SerializationManager
class to implement HIT serialization.
HomeInventoryTracker is no longer
a Singleton.
Merge branch 'master' of https://github.com/cletusw/hit.git

Conflicts:
	src/model/HomeInventoryTracker.java
Merge branch 'master' of https://github.com/cletusw/hit.git

Conflicts:
	src/model/HomeInventoryTracker.java