Free variables should be implicitly distinct

[lvh]

Right now, multiple fresh variables are not implicitly distinct. For example, with the events [{:ip "10.0.0.1"}], the query '(= (:ip x) (:ip y) "10.0.0.1") will (correctly!) result in: [[{:ip "10.0.0.1"} {:ip "10.0.0.1"}]]. While this is correct from a logic program perspective, this is probably not what the SOC wants. We can solve this by applying distincto to all of the logic variables.

[lvh]

This of course gets combinatorically worse once you add more logic variables.