trigger records should not be merged ever.  May need to restrict merging to single runs

In the short run, merging needs to be restricted to a single run - at least for HDF5.
Suggest making the merging code spit out a list of the runs included if > 1 and stop,  Require user to split into runs.  Possibly make --run a required parameter and stuff the run into the query? 
Longer term, could determine the runs in a query, then run submerges for each one. 