Remove/deprecate Tumbler::visibleItemCount

Arbitrary model item count, control geometry, and configurable fonts make the concept of "visible item count" a bit confusing and problematic. I'm always unsure what to specify, and seeing the property immediately raises questions like:

• What if the items don't fit? Do they overlap?
• Why can't Tumbler calculate a suitable value for me?
• What if the model item count is less than the visible item count?

Therefore, I'd like to propose removing/deprecating the visibleItemCount property. Tumbler should calculate something that fits the available geometry. Furthermore, there probably should be a bool wrap -property that is by default:

• false when the model item count is less than the calculated ideal visible item count
• true when the model item count is greater or equal than the calculated ideal visible item count
  This implies that we either implement non-wrapping PathView, or add an internal helper type that automatically chooses between PathView and ListView. This way Hours+Minutes+AM/PM type of tumblers would work nicely out of the box: http://blog.ittybittyapps.com/images/posts/lifting-the-lid-on-ios-7s-uipicker/UIDatePickerComparison.jpg