Updated documentation.
Renamed Factories.java to Builders.java.
Prepared Person class for persistence.
Minor API changes.
Added "UNSPECIFIED" enum to instances of enum.
Added persistence units.
Revert "Added persistence units."

This reverts commit 5f7bc5b18d8ac3dc81e41a992824b70759d8d9ab.
Revert "Revert "Added persistence units.""

This reverts commit d9fef1a97197cd14d6fd08131e1ae322a924a501.
Added debugging properties to persistence unit.
Prepared implementation for testing.
Added new test case.
First pass to make PersistenceManager work.
First pass to get formatting with Jindent working.
Added class to test PersistenceManger.
Merge branch 'feature-jpa-implementation' of https://github.com/axlm/Entity into develop

* 'feature-jpa-implementation' of https://github.com/axlm/Entity:
  Added class to test PersistenceManger.
  First pass to make PersistenceManager work. First pass to get formatting with Jindent working.
  Added new test case.
  Prepared implementation for testing.
  Added debugging properties to persistence unit.
  Revert "Revert "Added persistence units.""
  Revert "Added persistence units."
  Added persistence units.
  Added "UNSPECIFIED" enum to instances of enum.
  Minor API changes.
  Renamed Factories.java to Builders.java. Prepared Person class for persistence.
  Updated documentation.