Fix the transparency affected for parallaxed views, updated documentation.

Fixed up typos in demo and documentation.

Fixed a few more warnings.
Fix issue with parallax views when you would sometimes scroll down, then back up all the way, and the top view would stay parallaxed when it shouldn't be.

The previously-parallaxed views are now reset when they should no longer be parallaxed (both the offset and the alpha transparency).
Add an option to DragSortListView to enable dragging list items outside the bounds of the list view.

Add a demo for this feature, that deletes the items that are dragged off screen after a time out.
Remove spammy logcat from previous commit.