*Semantic change*: when unpickling the instance variables of an

*Semantic change*: when unpickling the instance variables of an
instance, use inst.__dict__.update(value) instead of a for loop with
setattr() over the value.keys().  This is more consistent (the
pickling doesn't use getattr() either but pickles inst.__dict__) and
avoids problems with instances that have a __setattr__ hook.

But it *is* a semantic change (because the setattr hook is no longer
used).  So beware!