Technical notes on version 1.23 16Jul02
                      17 July 2002
                      Kern Sibbald

General:
- Added support for autoloaders

Changes submitted this submission:
- Added changer support to devices.c
- Allow user to change Slot in the Volume record.
- Implemented code in lib to run an external program
  (tape changer)
- Implemented a changer script for mtx.
- Currently the changer commands used are:  
    loaded -- returns number of slot loaded or 0
    load   -- loads a specified slot
    unload -- unloads the device (returns casette to slot)
- Other changer commands defined but not yet used:
    list   -- returns list of slots containing a cassette
    slots  -- returns total number of slots 
- Implemented ChangerCommand, specified in the SD Device
  resource, permits editing of:
      %% = %
      %a = archive device name
      %c = changer device name
      %f = Client's name
      %j = Job name
      %o = command
      %s = Slot base 0
      %S = Slot base 1
      %v = Volume name
- Implemented ChangerTimeout default 60 seconds. It is 
  specified in the SD Device resource.