Feature refresh control

Custom Refresh Control that can be added on a UIScrollview based class. i.e. UICollectionView

tasks:

* [x] Example
* [x] replace case when no custom image is given. Custom images to be bundled or custom View that can be rotated
* [ ] Code review
customRefreshControl: property name is misleading.. better to start with verb as it handles a functionality
e.g. useCustomRefreshControl