version3:
chg: better detection of local paths in "swsubst dr path"
bugfix: calling format "swsubst dr -" or "swsubst dr /d"
add: unit swapping, to enable the swapping of floppies
add: disk cache flushing for SMARTDRV v3 and v4,& HyperDisk v4.56
bugifx: "subst /d" emits help screen

version2:
add: search/display the driver chain
add: search/display the MCB chains
bugfix: "/w" command
add: German NROFF doc files
add: '/x=' option to exclude drives from being searched while ::label:

version1:
intial revision
