Updated log statement.
Switched onOptionsItemSelected to onMenuItemSelected for more
generality; ScreenLayout now has a "scroll" option to make a layout
scroll automatically if it's too big for the screen.
Timers always use the main looper, so they always fire on the GUI
thread.
Added getSelectedItem method that returns the proper type.
Added subtitle capability when the adapter is used in a ListView.
Added getSelectedItem method; added support for an "empty message" when
the list is empty.
Updated target API to 17 (still keep minimum at 8).