It's basically there to prevent random facet id's being hard-coded elsewhere in the code, and to keep them in a unified location.  What we want to avoid is code in a random plugin doing if( facetId.equals("wonka.max")) { xyz}

So any facet that astools knows about or may know about is added here. This gives us a central location to store all facet id's we know, and to ignore ones we don't.  Basically it's just here to filter out facets that we've never heard of and have not customized a response for.  If wonka.max is in the workspace, astools is not currently giving out a customized set of jars for wonka.max, so we can just quickly return the default client-all set. 

If we do decide to customize wonka.max,  then its now a known facet *within astools*  and we can add it to the known list, and later check for customizations.