Allow adding OnScrollListener while supporting onMoreAsked
Hide empty view on progress (no overlaying of empty view)
Make gridview sample layout resemble listview's one
Show progress SwipeToRefresh progressbar by margining the empty view from top by progressbar's height

Backport: Set adapter and clear for concrete implementation of AbsListView, SwipeDismiss uses nineoldandroids now + MotionEventCompat voodoo
Merge branch 'dev'

Conflicts:
	SuperListviewLibrary/src/main/java/com/quentindommerc/superlistview/BaseSuperAbsListview.java
	SuperListviewLibrary/src/main/res/layout/view_progress_gridview.xml