Function:   Qualify()

               Qualify() is used to expand a filename to a fully
               filled drive:\path\filename combination. It uses a
               (non-documented) DOS function to achieve that,
               I've had no problems to date with it. It can come
               in handy in numerous situations.

   Syntax:     qualify(<cFileName>) --> cFullName

   Arguments:  <cFileName> is the filename you want to qualify.

   Returns:    The fully qualified string or NULL string if there
               was an error in the original name (invalid file name,
               malformed path). Qualify(), however, also recognises
               a possible new Path or Filename, which is thus
               considered legal.

   Usage:      Qualify is useful to attach a full path to a
               filename, so that when changing directories, the
               filename still applies to the same file. One good
               example is using it with Submitfile(), for
               enqueing files to be printed.

Some Notes on Qualify():
*   The input path need not actually exist, as
    one may want to use it to expand a file/path
    to be created.

*   Letters are Uppercased, Forward slashes become
    backward slashes, asterisks become question marks,
    directory and file names are truncated to 8 letters
    with a 3 letter extension, eventual .'s and ..'s in
    the path are resolved.

*   On local drives, the filespec returned always starts
    with D:, on network drives it always starts with
    \\<Machine>, and not the current drive mapping.

*   When qualify is done on a JOINed, SUBSTituted or
    ASSIGNed drive. The combination returned is one that
    would be required when any of those commands is not
    active. This could lead to some problems on network
    drives.