Started working on a plot system
Planets are now generated from scenes, and the plot can now be advanced in a simple way
Refactored the plot integration, now it's more according to the E-C design pattern.
Started on a spaceship
Now MEET actions also work in-game
Merge branch 'dev' of https://github.com/ravertass/KandidatRoguelike into dev

Conflicts:
	se/chalmers/roguelike/Engine.java
	se/chalmers/roguelike/Entity.java
	se/chalmers/roguelike/InputManager.java
	se/chalmers/roguelike/Systems/RenderingSystem.java