Use Cursors directly when binding documents.

Instead of creating a DocumentInfo for every list item, bind the
adapter against Cursor directly.

Create new SortingCursorWrapper which performs sorting at query time
and keeps a O(1) mapping from sorted to unsorted positions in the
underlying Cursor.

Suppress extra loader passes that had been kicked off.  Use unstable
provider when querying to guard against broken providers.

Bug: 10567506, 10510851
Change-Id: I535814da6b17c38de04a1175e0afcc78c6b966ce