Clean up to no longer use old APIs, add new loader throttle sample.

The new sample code is a complete self-contained end-to-end
implementation of a content provider populating a list view
through a loader, dynamically changing its contents based on
user input in about 500 lines.

Once the framework support is implemented, this will demonstrate
using CursorLoader's new throttling feature.

Change-Id: Ia67da7284607477125c613c3135f93bc1d95d0cb
5 files changed