14.0.0

• bn::regular_bg_map_item and bn::affine_bg_map_item can reference multiple maps per item.
• Regular and affine backgrounds import support multiple maps per image thanks to the optional height field.
• bn::regular_bg_animate_action and bn::regular_bg_cached_animate_action added.
• bn::affine_bg_animate_action and bn::affine_bg_cached_animate_action added.
• bn::pool of trivially destructible types can be destroyed without being empty.
• bn::list and bn::forward_list destructors fixed and optimized for trivially destructible types.
• Deprecated methods removed.