cmd_addactor

command: /addactor

quick ref:

/addactor [npc|camera]

description:

 add a new actor to the current active scene
/addactor			add a default npc entity to the current scene
/addactor npc		add a default npc entity to the current scene
/addactor camera	add a default camera entity to the current scene

添加一个新演员当前活动的场景中。