Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 Arg1 :: Arg2

 ::(Arg1, Arg2, Arg3)

 ::(Arg1, Arg2, Arg3, Arg4)

 to(Arg1, Arg2)

 to(Arg1, Arg2, Arg3)

 start_aspect_event_dispatcher(Arg1)