methods.

Initial patch by Brandon Milam.

_testmultiphase and xxlimited now use tp_traverse and
tp_finalize to avoid reference leaks encountered when
combining tp_dealloc with PyType_FromSpec (see
issue #16690 for details)

For details, see:
PEP 0485 -- A Function for testing approximate equality

Functions added: math.isclose() and cmath.isclose().

Original code by Chris Barker. Patch by Tal Einat.

PyObject_IsInstance(), PyObject_RichCompareBool() and _PyDict_Contains()
to check for and handle errors correctly.

in builtin and _crypt modules.

Original patch by David Moore.

patches by Matt Joiner and Alexey Kachayev.

- missing DECREF in PyModule_FromDefAndSpec2
- missing DECREF in PyType_FromSpecAndBases2
- missing DECREF in _testmultiphase module

Patch by Petr Viktorin

Known limitations of the current implementation:

- documentation changes are incomplete
- there's a reference leak I haven't tracked down yet

The leak is most visible by running:

  ./python -m test -R3:3 test_importlib

However, you can also see it by running:

  ./python -X showrefcount

Importing the array or _testmultiphase modules, and
then deleting them from both sys.modules and the local
namespace shows significant increases in the total
number of active references each cycle. By contrast,
with _testcapi (which continues to use single-phase
initialisation) the global refcounts stabilise after
a couple of cycles.

The new private C function makes no permanent changes to the environment
and is #ifdef'd out on non-Windows platforms.

Fixed segmentation fault in sqlite3.Row constructor with faked cursor type.
Fixed system error in the comparison of faked types.SimpleNamespace.

Replaces the PyList_GET_ITEM and PyList_SET_ITEM macros with normal array
accesses.  Replace the siftup unpredicatable branch with arithmetic.
Replace the rc == -1 tests with rc < 0.  Gives nicer looking assembly
with both Clang and GCC-4.9.  Also gives a small performance both for both.

module now support pickling.  Added readable and evaluable repr for these
objects.  Based on patch by Josh Rosenberg.

ElementTree.

Hopefully this will allow the PPC64 PowerLinux buildbot to finish a test run.

deprecated.  Based on patch by Mark Dickinson.