Structure refactor, race, sorter.

Also changed acceptance tests: removed first line in start and finish time files, no longer needed.
Sorter and subclasses is now ModelInitiator. Race and subclasses, RaceEvent handles only participants.
Lap is now a private class in Race, since it's only purpose is to abstract laps in a race.
Lots of small fixes and restructuring, removed code that is not needed. 

Formatter is gone, yes, yes, yeah!