For version control, as part of commit, should keep track of the application and method name that began an event.
EventParents now keep track of the Endpoint that created them.  These
endpoints will later be used to generate principal uuid of commit
message from root's endpoint.  Still need to actually push these
changes into emitter, instead of just supporting libraries.
Emitter now adds info on which endpoint is root of event.
Each event now tracks the method name that generated it.  Will be useful for version control.