Update to OOP facilities. * scripts/general/isa.m: Fixed isa so that multiple layers of class hierarchy are reported correctly. * src/variables.cc: Make exist('obj') for objects report correctly. * src/ov-base.h: Added an assign method so ov-class is able to assign structure elements properly. * src/ov-class.h: Assign map elements. * src/ov-class.cc: - Made sure that there are no duplicate classes in parent tree. - Simplified search algorithm for parent classes. - Fixed subsasgn so cls = method(cls,value) works when properly when method is a parent-class method. - Added __isa_parent__ so isa works correctly.

Wayne Bequette <bequette@bequette.che.rpi.edu>
Michel Berkelaar <michel@es.ele.tue.nl>
Larry Biegler <biegler@cmu.edu>
Yuris Fuentes <yuris@matias.colorado.edu>
Jeff Kantor <jeffrey.kantor@nd.edu>
Keith Levien <levienk@ccmail.orst.edu>
Danny Lewin <cerdldl@technion.technion.ac.il>
Michael Liebman <mjliebman@amoco.com>
Wolfgang Marquardt <maq@Prandtl.lfpt.rwth-aachen.de>
Buff Miner <miner@hagar.ph.utexas.edu>
Ashutosh Patwardhan <ashu@shell.com>
Larry Ricker <ricker@chevax.cheme.washington.edu>