Added logic to cache the SectionType due to a jpa bug where a thread
takes a reader lock but then can't acquire a write lock on the cache.
Change the Path class to using 'toName' rather than 'toString' to bring
it into alignment with the SingularAttribute convention.
cacheing section type to get around a jpa bug.
implemented CrudEntity interface so we can create a crud for Activity
entity.
Changed to method name on Path classe.
Added a child crud for Activities - nice!
upgraded to javax.persistence 2.1
removed whitespace.