Updates for SumStats API to deal with high memory stats.

- The code is a mess and will need to be cleaned up, but the
    tests do pass.

scripts/base/frameworks/sumstats/non-cluster.bro

@@ -6,13 +6,19 @@ event SumStats::finish_epoch(ss: SumStat)
 	{
 	if ( ss$name in result_store )
 		{
+		local now = network_time();
+
 		if ( ss?$epoch_result )
 			{
 			local data = result_store[ss$name];
 			# TODO: don't block here.
 			for ( key in data )
-				ss$epoch_result(network_time(), key, data[key]);
+				ss$epoch_result(now, key, data[key]);
 			}
+
+		if ( ss?$epoch_finished )
+			ss$epoch_finished(now);
+
 		reset(ss);
 		}