Registry loading - allow config to select a certain neighborhood

InterMine admins may wish to show only a certain neighborhood - e.g. someone might want to configure their BlueGenes to show only MODs or only plants. This should be configurable in some way - perhaps part of a superuser portal?

Start by tracing the registry-loading entry point and how BlueGenes configuration is currently supplied. Decide where a neighborhood selection belongs and how administrators would set it, then verify that a configured instance shows only the selected neighborhood while preserving existing behavior when no selection is provided.

Written by the indexing model from the issue text.