dev:
- add documentation
- main() is more readable
fix:
- unmanaged errors:
- map parsing: error if color value is >255
- map parsing: load_textures(): check return value of xml_xpm_file_to_image()
- main.c: draw_screen(): check return value of mlx_new_image()
other details:
- dev: color_from_rgb(): change signature
- fix: nullize map in map_destroy
- change: change error message for read_all_text() errors
- change: change rotation speed
- change: add and use contant NOOBONUS_SPEED
