Support lists to return each row into a channel instead of an array

[go-aegian]

It might make sense, for :many queries to have another function that can return each row as it's being read to a send channel closing the channel before exiting the function as this could be helpful in the case of streaming

Also the current list function returns either []obj or []*obj and could also be more efficient to have a third option to return *[]obj

What do you guys think?