Issue #95: Use request code integer resources
Issue #95: Formatting
Issue #95: Use request code resources
Issue #95: Fix `testMenuItem()` to work with ActionBar
Issue #95: Initialize `filterRequest` and call `setEmptyListView()`
Issue #95: Can no longer cast `BaseballCardList` to `ListActivity`

Need to use `findViewById()` rather than `getListView()`.
Issue #95: Register the `OnListItemClickListener`
Issue #95: Refactor `testMenuItem()`

Refactor `testMenuItem()` for use with menu items which do not launch
another Activity.
Issue #95: Disable hidden menu items
Issue #95: `invalidateOptionsMenu()`