Multithread-safe version which uses HistoJ for vectors

This version of the JSON monitoring switches to edm::stream::EDAnalyzer and changes the structure written to JSON files to HistoJ per suggestions from the DAQ group. In addition to monitoring HLT accepts by path and processed events, it now also monitors L1 seed accepts, prescale accepts, rejects and errors by path as well as accepts by primary dataset.

Because the changes made by this module require corresponding changes in DAQ tools (hltd and Elastic Search), DAQ experts request that if possible, this change should go into a patch release on Monday or Tuesday rather than straight into the release used for MWGR8.