provide defintions of continuant fiat boundary subClasses and history

[zhengj2007]

All subclasses of 'continuant fiat boundary' have elucidations that specify that they are defined in relation to a material entity. This can be specified of 'continuant fiat boundary' for the sake of parsimony.

In addition, 'Continuant fiat boundary' has a definition, but its subclasses have elucidations. This is odd since elucidations are supposed to exist for classes that are somehow too basic for definitions, but classes are defined in terms of their parent classes, and so should not be more basic than those parent classes. Therefore, the definitions should be specified for subClasses of 'continuant fiat boundary'.

Same comment applies to 'history'. Need to provide the definition for 'history'.