Tested again a range of values for ROOT_VIRT_SIZE.  It seems 1x10^7 bytes is now the best compromise for fast sorting while still leaving my laptop usable.  Changed default to this.
Improved formatting of list of files at start of run.
Added Verbose (-v) and Quiet (-q) modes to command line options
Modified main() to respond to -v and -q
Modified Calib() and CalibOffline() to respond to -q and -v