Update references to Python docs in the sidebar index.
Patch contributed by Auke Willem Oosterhoff.
merge from 3.4

Update references to Python docs in the sidebar index.
Patch contributed by Auke Willem Oosterhoff.
Fix issue #21641: Close the socket before raising the SMTPResponseException. Fixes the ResourceWarning in the test run.

Patch by Claudiu.Popa.
merge from 3.4

Fix issue #21641: Close the socket before raising the SMTPResponseException. Fixes the ResourceWarning in the test run.
Patch by Claudiu.Popa.
Issue #21439: Fix a couple of typos.
Issue #21439: Merge with 3.4
Issue #21643: Updated test and fixed logic bug in lib64 symlink creation.
Closes #21643: Merged fix from 3.4.
All modern compilers provide a offsetof() function

offsetof() is used directly in many other .c files without any issue.
Issue #21119: asyncio now closes sockets on errors

Fix ResourceWarning: create_connection(), create_datagram_endpoint() and
create_unix_server() methods of event loop now close the newly created socket
on error.
Issue #21119: asyncio: Make sure that socketpair() close sockets on error

Close the listening socket if sock.bind() raises an exception.
Merge 3.4: Issue #21119, fix ResourceWarning in asyncio

* Make sure that socketpair() close sockets on error. Close the listening
  socket if sock.bind() raises an exception.
* asyncio now closes sockets on errors. Fix ResourceWarning:
  create_connection(), create_datagram_endpoint() and create_unix_server()
  methods of event loop now close the newly created socket on error.
cleanup test_asyncio/test_base_events.py: cm variable was unused
(Merge 3.4) cleanup test_asyncio/test_base_events.py: cm variable was unused
Issue #21651: Fix ResourceWarning when running asyncio tests on Windows.
Patch written by Claudiu Popa.
(Merge 3.4) Issue #21651: Fix ResourceWarning when running asyncio tests on
Windows. Patch written by Claudiu Popa.
Fix asyncio tests on Windows: wait for the subprocess exit

Before, regrtest failed to remove the temporary test directory because the
process was still running in this directory.
(Merge 3.4) Fix asyncio tests on Windows: wait for the subprocess exit

Before, regrtest failed to remove the temporary test directory because the
process was still running in this directory.
Issue #21326: Add asyncio.BaseEventLoop.is_closed() method

Add BaseEventLoop._closed attribute and use it to check if the event loop was
closed or not, instead of checking different attributes in each subclass of
BaseEventLoop.

run_forever() and run_until_complete() now raises a RuntimeError('Event loop is
closed') exception if the event loop was closed.

BaseProactorEventLoop.close() now also cancels "accept futures".
Issue #18409: Idle: add unittest for AutoComplete. Patch by Phil Webster.