Fulfill terminal height

When list is paginated, there is 3-lines empty at the bottom.
So I fixed it to be fulfilled.
(By the way, percol is also fulfilled)

![Comparison screenshot](http://gyazo-yuyat.heroku.com/81091094801167a45541929acd3ec210.png)
(Left: current peco, Center: peco patched by me, Right: percol)

Is there any reason for this empty lines?