FirstName and LastName property types

[maeve]

We commonly have to translate between data structures that store a person's name as a single string and structures that split the name into first name and last name.

It would be nice if modelish could abstract away the boilerplate by doing something like this:

    property :customer_first_name, :type => FirstName, :from => :input_name
    property :customer_last_name, :type => LastName, :from => :input_name

The format for the input string should default to "first last", with some kind of configuration option to override that.