add minimum width property, decorated images, and border color

[logansease]

Needed to add more customizable UI to this segment.
I've added the following:

• a minimumWidth property to style
• a selectedBorderColor property to style
• a new set titles method that also takes an array of selected and normal images that will decorate the right side of the segment bar

[TBXark]

PinterestSegmentCustomizeDelegate has not referenced by other in the code. Is this a necessary protocol ?

[logansease]

sorry @TBXark I didn't mean to leave that code there. It's been removed.
I have also added a new normalBorderColor property and a convenience initializer for the image fields

[TBXark]

Thanks, This looks good, after I merge the code I will add the add some demo code to the example.