Add podspec, adjustment to visiblePages calc, and new property

Good morning,
I added a podspec along with the following changes for your approval:

1. Added a BOOL property to enable/disable the border around the scrollview
2. I made an adjustment to the visiblePages calculation in the reloadData method. I check to see if the self.frame.size.width is evenly divisible by pageSize. If true then I increment visiblePages by 1. I found that the contentSize of the scrollView is too small (by 1) if I don't perform this check. Example: self.frame.size.width = 320 and pageSize = 320

Thanks!!!