(PDB-254) Change benchmark to mutate catalog resources and edges send a defined number of messages

Previously benchmark.clj when it would mutate a catalog would only add a single resource.  This change will add a new resource or mutate a random existing resource.  It will also add a new or change an existing edge.  One of these four mutations is picked at random.  This commit also adds a new parameter to benchmark.clj to allow the syncronous sending of a specified number of commands (per host) via the -N argument.

After talking with @kbarber, it looks like report submission stuff is broken in the current benchmark.clj as it resubmits the same report multiple times to a single host.  This causes the report to hash the same and causes unique index failures.  I have added a function to modify start/end time and configuration version, so this should work now in the new code and the existing interval code.