* node number/node count support

ruby/lib/jam_ruby/jam_track_importer.rb

@@ -2110,7 +2110,28 @@ module JamRuby
         end
 
         jam_tracks.each do |jam_track|
-          importers << generate_mp3_aac_stem(jam_track)
+
+          if ENV['NODE_COUNT']
+            node_count = ENV['NODE_COUNT'].to_i
+            node_number = ENV['NODE_NUMBER'].to_i
+            raise "NO NODE_COUNT" if node_count == 0
+
+            jam_track_id = jam_track.id.to_i
+            jam_track_id = jam_track_id + node_number
+            if jam_track_id == 0
+              @@log.warn("skipping #{jam_track_id} because non-numeric ID")
+              next
+            elsif jam_track_id % node_count == 0
+              @@log.warn("starting JamTrack #{jam_track.id} (#{jam_track_id})")
+              importers << generate_mp3_aac_stem(jam_track)
+            else
+              @@log.warn("skipping #{jam_track_id}")
+              next
+            end
+          else
+            importers << generate_mp3_aac_stem(jam_track)
+          end
+
         end
 
         @@log.info("SUMMARY")