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"