file_id	IN:	File identifier returned by Hopen
	vgroup_id	IN:	Vgroup identifier returned by Vattach

	Purpose	Remove a vgroup from a file.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) if not successful.
	Description	Vdelete removes the vgroup identified by the parameter vgroup_id from the file identified by the parameter file_id.
		This routine will remove the vgroup from the internal data structures and from the file.

	FORTRAN	integer function vdelete(file_id, vgroup_id)
		integer file_id, vgroup_id