Entity directives

• built_in/0
• category/1-4
• dynamic/0
• end_category/0
• end_object/0
• end_protocol/0
• include/1
• info/1
• initialization/1
• object/1-5
• op/3
• protocol/1-2
• set_logtalk_flag/2
• threaded/0
• uses/1
• use_module/1