Stubbing `UserContext` and updating tests.

See #29
Finishing stubs for `AuthoredItem` and fixing error.

getUniqueId() is final on the parent, and doesn't need to be
reimplemented.

See #29
Writing UniqueId and added constructors.

Constructors can randomly generate a UniqueId, or build one from a
UserContext.

See #29.
Stubbing QAController.

Throwing `UnsupportedOperationExceptions` in unimplemented methods.

See #29
Stubbing DataFilter class.

Added the trivial implementation details. Logic bits still needed.

See #29
Stubbing `DataManager`.

See #29
Updating some out of date object names.

No longer have `IQAModel` and `IItemFilter`
Stubbing data source manages.

`LocalDataSourceManager` and `NetworkDataSourceManager`

See #29
Updating reference to `UserContext` in tests.
Updating test cases to work with Junit3

The test case function must start with (case sensitive) `test_` and the
setup function must be called `setUp()` (again case sensitive).
Updating attachment data type to Byte[]
Removing `IUpvotable` interface.
Stubbing `IncrementalResult`.

See #29
Rename IncrementalObserver to IIncrementalObserver.

See #29
Removing references to IUpvotable.
Updating references to IncrementalObserver.
Updating references to IncrementalObserver in halfcaff.
Fixing naming issues.

Constants and enums should be ALL_CAPS.