Catalog:  Dissociated dkey retrieval from datapoint retrieval

Now datapoints can ONLY be grabbed by one distinct DKey at a time.  This
makes easier the process of grouping datapoints by dkey for retrieval.
The dissociation of DKey allows for dkeys to be sorted separately in a
different table under a hierarchical model, for wildcard matching and
retrieval, instead of this messy shell-based globbing.
Next, the variable/wildcard dkey retrieval (while dkeys are still associated with
individual datapoints as well, for regular retrieval) needs to be stored
into a different table with keys that are NOT pruned for hierarchical
searching and matching, for the GetDKey routines.