When setting selected date, -pagingEnabled is not taken into account

Hi!

What I do when using this control is to pre-set the selected date to a relevant date in my -viewWillAppear.

I noticed though that the selected date row is anchored to the bottom or top, even if `pagingEnabled` is set to `YES`.

I am not sure if this is intended behavior, or unintentional.

My preference is that if scrolling by the user snaps to the month, setting selected date programmatically should do the same.

Attached a patch to do it. It may be the completely the wrong way to go about it, I'm still a bit of a UIKit noob, in which case I apologize in advance :)

Cheers!
Leon