Enabled SDL_image's support for PNG and TIFF files and improved the

AssetManager with a hashing function, a linked list structure to store
the hashes as well as a reference counter to support multiple users
sharing the same asset.

include/AssetManager.h

@@ -5,7 +5,11 @@
 #include "SDL_mixer.h"
 #include "SDL_render.h"
 #include "reusable_ids.h"
-#include <stdint.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif // !__cplusplus
 
 typedef enum {
   ASSET_TYPE_IMAGE,
@@ -19,10 +23,14 @@ typedef struct asset_manager AssetManager;
 AssetManager *create_asset_manager();
 AssetID load_asset_to_manager(AssetManager *am, const char *path,
                               AssetType type, Renderer *renderer);
-void remove_asset_from_manager(AssetManager *am, AssetID id);
+void remove_asset_from_manager(AssetManager *am, AssetID *id_ptr);
 SDL_Texture *get_texture(AssetManager *am, AssetID id);
 Mix_Chunk *get_audio_chunk(AssetManager *am, AssetID id);
 Mix_Music *get_music(AssetManager *am, AssetID id);
 void destroy_asset_manager(AssetManager *am);
 
+#ifdef __cplusplus
+}
+#endif // !__cplusplus
+
 #endif // !ASSET_MANAGER_H