Patch by Antoine Pitrou (based on Robin Schreiber's original patch)

 -I

    Run Python in isolated mode. This also implies -E and -s. In isolated mode
    sys.path contains neither the script’s directory nor the user’s
    site-packages directory. All PYTHON* environment variables are ignored,
    too. Further restrictions may be imposed to prevent the user from
    injecting malicious code.

For 3.3, we just deleted the example.  In 3.4 it was fixed.

Also, document the policy keyword that was added to Message in 3.3.

This was triggered by wanting to make the doctest in email.policy.rst pass;
as_bytes and __bytes__ are clearly useful now that we have BytesGenerator.
Also updated the Message docs to document the policy keyword that was
added in 3.3.

#18581: remove duplicate test and run a test class that was skipped.  Initial patch by Vajrasky Kok.

#18273: move the tests in Lib/test/json_tests to Lib/test/test_json and make them discoverable by unittest.  Patch by Zachary Ware.

in Modules/posixmodule.c is now far more robust.

Issue #18621: Prevent the site module's patched builtins from keeping too many references alive for too long.

#18443: remove the TextMate entry now that the bundle has been removed and fix ordering.  Patch by Févry Thibault.

RGB -- YIQ conversions so that they match the FCC NTSC versions.

Letting the compiler decide how to optimize the multiply by five
gives it the freedom to make better choices for the best technique
for a given target machine.

For example, GCC on x86_64 produces a little bit better code:

Old-way (3 steps with a data dependency between each step):

    shrq    $5, %r13
    leaq    1(%rbx,%r13), %rax
    leaq    (%rax,%rbx,4), %rbx

New-way (3 steps with no dependency between the first two steps
         which can be run in parallel):

    leaq    (%rbx,%rbx,4), %rax     # i*5
    shrq    $5, %r13                # perturb >>= PERTURB_SHIFT
    leaq    1(%r13,%rax), %rbx      # 1 + perturb + i*5

Issue #17934: Add a clear() method to frame objects, to help clean up expensive details (local variables) and break reference cycles.