Working FS delete for /OriginalFile specs

This currently does *too much*, in that asking to delete
any file in a fileset, will delete the entire fileset --
without warning! But at least it gives us the option of
providing an alternate spec like "/OriginalFile+FS".

Note: this will not yet take into account the actual file
structure, nor is that really tenable unless with link
OriginalFiles to OriginalFiles. Further, since directories
are not related to the Filesets, it will be possible to
delete them and thereby leave the rest of the fileset
"lost"!!