Ctools relationship plugin for taxonomy entity index

With the use of the taxonomy entity index table, we can easily provide a ctools relationship context handler that can itself restrict on vocabularies and field usage. This relationship then could be used in panels, page manager, panelizer to pass related terms to views and so on.

Such a ctools plugin is already implemented for the core taxonomy_index. The same approach can be used for the taxonomy_entity_index.

I'll post a patch for that in the next comment.