Make Name properly immutable

[nresare]

The public API of Name is immutable, meaning that there are no methods that can be used to change the state of a Name instance once constructed. However, as an implementation detail of how the public constructors populate the fields of the class, they end up calling private api that modifies state repeatedly.

Having only final fields in immutable objects is good house keeping, but unfortunately test coverage is not very high for Name so it is a bit scary to do refactoring work. Getting to, or close to 100% unit test coverage and then update the implementation to allow for using the final modifier with all fields would be a neat contribution in my opinion.

[ibauersachs]

I made significant changes to Name in fecf898, among others a Name derived from another no longer shares the same data.

While full immutability would be a nice to have, I don't think it'd be wort the effort and trade-offs. All methods called from the constructor would need to be static, require intermediate objects for the to-be-final fields (due to the lack of multiple return or out-values in Java).