Improve descriptive annotations of BFO entities

[zhengj2007]

There is a lot of descriptive metadata for the classes of the BFO, including as values of definition, editor note, elucidation, example of usage, and has associated axiom(fol) properties. Information resembling definitions is often interspersed among other types of clarifying information in the elucidation and editor note fields of the classes. The descriptive annotations of BFO entities need to be improved and consistent cross different annotations.