Feature/slide

Added features to slide the view.
- Swipe the panel.
- Added support to detect AbsListView and scroll on reaching top.
- Added support for anchor view at a position.

View dragging has been simplified and modified based on the View below.
https://github.com/fedepaol/dragqueen/blob/master/app/src/main/java/com/whiterabbit/dragqueen/OuterLayout.java