Message2784

My understanding is that decode should return unicode objects since it's turning an encoded sequence of bytes into unicode characters.  However, I don't see why datetime should care if it gets a str or a unicode object for unpickling.  So I'd prefer to fix this with the patch I'm attaching.  

Instead of changing all of the decode methods to return a PyObject, I just changed all of the isinstance checks for str to use basestring instead.  str and unicode both descend from it.  Sound good?
File Added: datetime_unpickle_basestring.patch