Merge with 3.4.

pydoc.gui was removed over 3 years ago (#10818), this script has been
utterly bereft of worth since then.

private tasks in gather().

in gather().

_on_handshake() method

The _SelectorSslTransport constructor already calls it.

The _SelectorSslTransport constructor already calls it.

Fix regression that this test would have caught.

in debug mode

sys.stderr, to get output even if tests are run with the -j command line
option.

* Tulip issue #184: Log subprocess events in debug mode

  - Log stdin, stdout and stderr transports and protocols
  - Log process identifier (pid)
  - Log connection of pipes
  - Log process exit
  - Log Process.communicate() tasks: feed stdin, read stdout and stderr
  - Add __repr__() method to many classes related to subprocesses


* Add BaseSubprocessTransport._pid attribute. Store the pid so it is still
  accessible after the process exited. It's more convinient for debug.

* create_connection(): add the socket in the "connected to" debug log

* Clean up some docstrings and comments. Remove unused unimplemented
  _read_from_self().

test purposes are now reflected in GrepDialog and ReplaceDialog.  Docstrings
are improved. Initial patch by Saimadhav Heblikar

broken by the fix for security issue #19435.  Patch by Zach Byrne.

broken by the fix for security issue #19435.  Patch by Zach Byrne.

broken by the fix for security issue #19435.  Patch by Zach Byrne.

broken by the fix for security issue #19435.  Patch by Zach Byrne.

Contributed by Anton Barkovsky.