Fixe: crash on Path when there is a valid path without waypoint (already at destination)
Renderer: Map/BuildTile/WalkTile surface generation is splitted into other functions
Renderer: Cleaning color becomes red
Fixe: Flush all events before starting main loop
Fixe: int overflow in Camera::Update()
Fixe: boundary check in World::UpdateAccessible/Walkable..()
Camera default location is set to (0, 0)
Fixe: Unit position in World::Init() isn't relative to screen anymore
Fixe: Bad #undef in SpriteDesc
Camera: More checks before setting pos with SetPos()