Basic 4.2, Messages: 3.3.2: Allow other gender strings

[Michael Jones]

In some jurisdictions, gender strings other than "male" and "female" will be required under some circumstances.

Change the spec to allow other strings, but to continue to define the values "male" and "female".

[Michael Jones]

Fix #282 Basic 4.2, Messages: 3.3.2: Allow other gender strings

→ 317cb0c741a1