Minor doc fix in urllib.parse.rst
merge from 3.3. Minor urllib.parse.rst docs fix.
Issue #18594: Fix the fast path for collections.Counter().

The path wasn't being taken due to an over-restrictive type check.
merge
Close #19092: ExitStack now reraises exceptions from __exit__

Report and patch by Hrvoje Nik?i?
Merge #19092 from 3.3
Close #10042: functools.total_ordering now handles NotImplemented

(Patch by Katie Miller)