More unit test fixes.
Fixed the rest of the unit tests in PersonTests.cs. Added a default list of numbers to cover some of the test.
Added another set of default numbers for use in the other complicated tests in PersonTests.cs.
Fixed up the tests in PersonVerbEndingTests.cs.
More work on the implementation of BuildPluralVerb. Words like identify and address are now pluralised correctly.
Added a couple of other plural tests and added a default list of numbers.
More unit test changes. Some tests have been commented out as they require a correct test case.