logilab-aspects #2865 nice traceback [open]

Avoir des beaux tracebacks quand une erreur se produit dans la méthode aspectée. (Actuellement, on a le traceback de l'exception en double). Par exemple

Traceback (most recent call last):
  File "contract_example.py", line 188, in ?
    run()
  File "contract_example.py", line 158, in run
    stack.push(1)
  File ".../cvs_work/soft_public/logilab/aspects/weaver.py", line 222, in wrapper
    ret_v = aspect.around(wobj, context, *args, **kwargs)
  File ".../cvs_work/soft_public/logilab/aspects/core.py", line 92, in around
    return self._proceed(wobj, wclass, met_name, *args, **kwargs)
  File ".../cvs_work/soft_public/logilab/aspects/core.py", line 99, in _proceed
    return method.im_func(wobj, *args, **kwargs)
  File "contract_example.py", line 105, in push
    raise Exception("heheheheh")
Exception: ('heheheheh', '  File ".../cvs_work/soft_public/logilab/aspects/core.py", line 92, in around\n    return self._proceed(wobj, wclass, met_name, *args, **kwargs)\n  File ".../cvs_work/soft_public/logilab/aspects/core.py", line 99, in _proceed\n    return method.im_func(wobj, *args, **kwargs)\n  File "contract_example.py", line 105, in push\n    raise Exception("heheheheh")\n')
prioritynormal
typeenhancement
done in<not specified>
closed by<not specified>