Add a low FPS callback to aid in debugging, and fix a huge memory leak in akgl_text_rendertextat

include/akgl/game.h

@@ -37,6 +37,7 @@ typedef struct {
     SDL_Time lastIterTime;
     SDL_Time lastFPSTime;
     int16_t framesSinceUpdate;
+    void (*lowfpsfunc)(void);
 } akgl_Game;
 
 extern SDL_Window *window;
@@ -58,5 +59,6 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_game_init_screen();
 void akgl_game_updateFPS();
 akerr_ErrorContext AKERR_NOIGNORE *akgl_game_save(char *fpath);
 akerr_ErrorContext AKERR_NOIGNORE *akgl_game_load(char *fpath);
+void akgl_game_lowfps(void);
 
 #endif //_AKGL_GAME_H_