Merge the refactoring + box2d movement

CMakeLists.txt

res/map_split_island.h5

src/editor/main.cpp

src/game/combat/CombatEngine.cpp

src/game/combat/CombatEngine.hpp

src/game/combat/Weapon.cpp

src/game/combat/Weapon.hpp

src/game/core/Config.cpp

src/game/core/Config.hpp

src/game/core/Engine.cpp

src/game/core/Engine.hpp

src/game/core/GameManager.cpp

src/game/core/GameManager.hpp

src/game/core/Spritesheet.cpp

src/game/core/Spritesheet.hpp

src/game/entities/Building.cpp

src/game/entities/Building.hpp

src/game/entities/Bullet.cpp

src/game/entities/Bullet.hpp

src/game/entities/Unit.cpp