(PDB-446) Start in on the merge of v2 and v3 test namespaces

- Merged fact-names
- Merged resources
- Merged explore
- Merged nodes
- Created a new defixture macro for using a fixture (via
  clojure.test) that could also be invoked directly as a fn
- Fixed the failing resources tests
Switched fact subquery tests from vector results to sets.

Necessary because hypersql and postgres return (unordered) results
in a different order, so they must be compared in a way that ignores order
Merge pull request #850 from senior/maint/1.6.x/fact-names-http-test-merge

(PDB-446) Start in on the merge of v2 and v3 test namespaces