NAME
        BumpRevision - reformat a name for a second copy.

   SYNOPSIS
        result = BumpRevision(newbuf, oldname)
          D0                    A0      A1

        strptr bumprevision(strptr, strptr);

   FUNCTION
        BumpRevision takes a name and turns it into a "copy_of_name".
        It knows how to deal with copies of copies.  The routine
        will truncate the new name to the maximum dos name size
        (currently 30 characters).

   INPUTS
        newbuf - the new buffer that will receive the name
                 (it must be at least 31 characters long).
        oldname - the original name

   RESULTS
        result - a pointer to newbuf

   EXAMPLE
        oldname                          newbuf
        -------                          ------
        "foo"                            "copy_of_foo"
        "copy_of_foo"                    "copy_2_of_foo"
        "copy_2_of_foo"                  "copy_3_of_foo"
        "copy_199_of_foo"                "copy_200_of_foo"
        "copy foo"                       "copy_of_copy foo"
        "copy_0_of_foo"                  "copy_1_of_foo"
        "012345678901234567890123456789" "copy_of_0123456789012345678901"