Bug 547787 - [ReferenceService] Object details in element selection dialog

Add a pluggable strategy to the DefaultReferenceService for provision
of the SelectionComposite to present in the dialog.

Provide a new plug-in implementing a SelectionCompositeStrategy that
renders a table with multiple columns described by a view model.

Change-Id: I68699309ae6f4d58b56636c13387e3e003931532
Signed-off-by: Christian W. Damus <give.a.damus@gmail.com>