add recon-mutil

[baltzell]

• Based on ConcurrentLinkedQueue event queues, and CompletableFuture I/O and processor threads
• Includes multi-threaded decoding, background-merging, and on-the-fly, in-memory post-processing
• Includes a scaling test mode, triggered by multiple thread counts, e.g.,-t 1,2,3
• Unlike recon-util:
  • the -i option is ignored and the trailing command-line arguments are required and treated as input EVIO/HIPO files (not a whitespace-separated, custom engine list)
  • the -c option is interpreted as a comma-separated, custom engine list (not a special/builtin engine list -c 0/1/2)
• Like recon-util, there is a default engine list, but it's a resource instead of embedded

Depends on:
#1436
#1435
#1434
#1421
#1419
#1418
#1417
#1416
#1414
#1413
#1412
#1411
#1409
#1406
#1403
#1396
#1395
#1391
#1390