[Python-3000] Enough with the u"string" already!

[Charles Merriam]

OK.  54 long messages into it, the argument is stuck at:

1.  But 3.0 code is different.
2.  But 3.0 shouldn't gratuitously break 2.6 code.

So make u"sting" a deprecated structure with a warning and kill it in
3.1.  Why write a novel about it?  Just make what programmers expect
to happen happen.


Charles