Refactor the story->camera converter to be a part of the camera.

camera.hpp

@@ -3,6 +3,10 @@
 #include "constants.hpp"
 #include <SFML/Graphics/RenderTexture.hpp>
 
+namespace components {
+  struct Storyboard;
+}
+
 namespace cinematic {
   struct Camera {
     animate2::Animate2 anim;
@@ -26,6 +30,7 @@ namespace cinematic {
     void style(const std::string &name);
     void reset(sf::RenderTexture& target);
     void update_camera_bounds(sf::Vector2f size);
+    void from_story(components::Storyboard& story);
   };
 
   void init();