Documentation fixes, including fixing "suspicious" problems.
Version bump for 3.4.0b3.
Added tag v3.4.0b3 for changeset a97ce3ecc96a
Close #20105: set __traceback__ when chaining exceptions in C
fix refleak on error
cleanup after custom buffer converter
Merge latest Tulip into asyncio
Issue #8260: The read(), readline() and readlines() methods of
codecs.StreamReader returned incomplete data when were called after
readline() or read(size).  Based on patch by Amaury Forgeot d'Arc.
Issue #8260: The read(), readline() and readlines() methods of
codecs.StreamReader returned incomplete data when were called after
readline() or read(size).  Based on patch by Amaury Forgeot d'Arc.
Merge heads
Fix issue #20367: concurrent.futures.as_completed() for duplicate arguments.
Patch by Glenn Langford.
Issue #19990: Added tests for the imghdr module.
Based on patch by Claudiu Popa.
Issue #19990: Added tests for the imghdr module.
Based on patch by Claudiu Popa.
Issue #20193: The zlib module now uses Argument Clinic.
Issue #20367: Add Glenn Langford to Misc/ACKS
Update docstring to mention correct PEP number.

This file hasn't been touched since its initial commit in 2006. In CPython
default branch (3.4), the relevant PEP number is 3333.
silence compiler warning that 's' may be used uninitialized in the load function.
Issue #20193: Fix commit r6f217456b9ba by including clinic/zlibmodule.c.h instead
of zlibmodule.clinic.c
Issue #20394: Attempt to silence CID 1164423: Division or modulo by zero in audioop_ratecv_impl()
Serhiy and I had the same idea so it's most likely right. ;)
Issue #20338: Increase allowed tip width slightly and wrap long signagure lines.
Original patch by Serhiy Storchaka.