Issues with swiping/dismissing list items (ContextualUndo and SwipeDismiss) 

1. The 'Current Removed View' was assigned in the Adapter's getView() method. 
However, the parent of this view was never set. Instead, items from the listview's 'activeViews' list were used instead and they never went through the 'getView()' for measuring again.  
Changed this by adding an onHierarchyChangeListener and picking up in the 'Current Removed View' in the 'onChildViewAdded' method.

2. Touch Child was never 'activated'.

3. Allow users of ContextualUndoAdapters to forcefully remove any pending item

4. Making the content and undo views INVISIBLE instead of GONE prevents some strange layout issues.  
If the 'content' or the 'undo' view is made GONE, the other view's layout changes because views that are GONE are never part of any measuring. E.g. swiping away the 'content' view can make the entire ContextualIUndoView less high if the 'undo' view has a different measurement that yields a lower height than the 'content's height.  
When these two views are made 'INVISIBLE' instead, the measurement of the ContextualUndoView never changes before, during or after a swipe and undo action.  
Also, the animation seems to be smoother when using INVISIBLE instead of GONE.

5. Fix issues related to recycling ContextualUndoViews as list-items related to animations.