Fixed a potential bug when the image name is nil.
Added and changed some delegate methods to notify when user starts dragging, is dragging and swiped.
Commented the `-swipeTableViewCell:didSwipeWithPercentageDelegate:` because it's very verbose.
- Changed the Product Name of the project.

- Added a fancy icon to the demo project.
Merge pull request #26 from alikaragoz/pr/23

- Fixed a potential bug when the image name is nil.