made changes to IMPORT_END (IMPORT_FINISH), added new events for parts specifically (PART_START and PART_FINISH), changed where events are dispatched to be more natural, kept backwards compatibilities by reusing the constant's values
updated importer to use the new event constant
Merge pull request #18 from cleentfaar/feature-updated-events-and-dispatching-of-events

Implemented consistent start/finish events for import and parts