-- WIP -- Dubit Coding Challenge stage 4 - Achievements --WIP--
Added a data driven Achievement manager and achievements.
Changed moles to contain 'type'.
Changed MoleHole to extend EventDispatcher so we get an event triggered on a mole being killed and surviving.

TO DO:
- Display achievements in summary screen.
- Colour (or other notification) when achievement achieved.
- Fix achievement status not updating during game. (Events not firing?).