Rules can be created from the UI
Game can be stopped/started from the UI
Current level can be reset (Load from file again)
Added "Game" target and main file
TODO (A lot):
- Unit tests
- Fully functionnal UI
- Win conditions
- Level background
- Level switching/progression
- Interesting and varied rules
- Multi-scale pathfinding
- etc
Entities are now managed with unique_ptr to allow polymorphism (and good memory management)
Rules can be added via the Level object
Fixed Rule::findTarget not caring about targetType
TODO : Find why pathfinding (unlikely) or findTarget (most likely) is broken