Added WFS layer which returns only Rottnest Shelf files.

This is to give a 1:1 correspondence between geonetwork records (i.e. 123 search results) and geoserver layers.

Required for BODAAC.

The way we've got it setup, there needs to be one layer per ACORN site (so that the portal doesn't have to do any CQL filtering) - so some other layers will need to be set up for ACORN.

@ggalibert come talk to me about this if you like.