Catalog:  add full dkey searching with wildcard functionality

New dkey table, new hierarchical sorting system, new lookup system
(similar to the old system with wildcard fields), new match structure
for datapoints

lookup system for dkeys with wildcard functionality is disgustingly
inefficient.  It needs some good tuning.  It's also not necessarily
robust.  I don't know how it will handle trying to find nonexistent
fields, but it should be alright.