Mark string.join() as done. Turns out string_join() works "for free" now,
because PySequence_Fast() started working for free as soon as
PySequence_Tuple() learned how to work with iterators. For some reason
unicode.join() still doesn't work, though.
diff --git a/Misc/NEWS b/Misc/NEWS
index d838c0f..0d7857f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -23,8 +23,9 @@
max()
min()
reduce()
- XXX TODO string.join(), unicode.join()
+ string.join()
tuple()
+ XXX TODO unicode.join()
XXX TODO zip()
XXX TODO 'x in y'