Document spectatee_status, disable 2d dmgtext for observers

I am not sure why observers sometimes don't know the location of players but this is a quick fix to get rid of the annoying 2d text. Note that radar doesn't check has_origin when drawing the locations so it shows them as if the observer knew where they are. Technically that's true since this happens with bots who stand still on their spawnpoint. Maybe has_origin is updated only when moving? I've seen 2d damagetext with players once though but it could have been someone shooting before moving.