kes Rework many features of DVD writing and reading. Added many error

     messages.  Most importantly changed part to represent the current
     part number base zero. This makes current DVD writing incompatible
     with previous version.
26Aug06
kes  Add host:port to connect failure messages to FD and SD from Dir.
kes  Add WhereACL to console ACL list.  If nothing is specified, only
     the default is permitted for restore. Otherwise, *all* allows any
     path, or you can specify permitted paths. This should allow control
     over where users can restore files. This is untested.
kes  Modified message to add a ? (as in loaded?) when querying the autochanger
     for what Slot is loaded.
kes  Fixed the use of Slot, so that is more correctly maintained, thus
     eliminating unneeded duplicate calls to determine what Slot is loaded.