Changed everything to return "undefined" to indicate non-handle. This
way I can pass back null from the unmarshaler which marshals {NULL:
true} to null.
unmarshalJson, takes a dynamodb formatted object and turns it into a
unmarshaled json string representation.
Added the rest of the unmarshal commands, hooked it up in the
marshalService, and went through and changed the word "null" to
"undefined" in a lot of the tests.