Test the refactored FilteredList<T> class.
Add missing file from last commit.
Test package refactoring in Sloop.
Update tests to support filters right in the data collection.
Remove tests for obsolete .util package.
Updated to match sloop changes -- DataEntry has an extra property
(filtered or not filtered).
Updated tests for new model implementation.
Added new files for tests.
Removed outdated import.
Refactor unit tests to test against the model interfaces rather than the
implementations.