Add a function to collect certificates from several certificate stores into one certificate collection store that is then enumerated. This ensures we load as many certificates as we can access.

Make it doing less memory allocations and using the modern C API.

Remove the PyMem_FREE() call added in cb90c89d.  The buffer will be
freed when PyTokenizer_Free() is called on the tokenizer state.

This reverts commit dfd775a0.

bpo-36443, bpo-36202: Since Python 3.7.0, calling Py_DecodeLocale()
before Py_Initialize() produces mojibake if the LC_CTYPE locale is
coerced and/or if the UTF-8 Mode is enabled by the user
configuration. This change fix the issue by disabling LC_CTYPE
coercion and UTF-8 Mode by default. They must now be enabled
explicitly (opt-in) using the new _Py_PreInitialize() API with
_PyPreConfig.

When embedding Python, set coerce_c_locale and utf8_mode attributes
of _PyPreConfig to -1 to enable automatically these parameters
depending on the LC_CTYPE locale, environment variables and command
line arguments

Alternative: Setting Py_UTF8Mode to 1 always explicitly enables the
UTF-8 Mode.

Changes:

* _PyPreConfig_INIT now sets coerce_c_locale and utf8_mode to 0 by
  default.
* _Py_InitializeFromArgs() and _Py_InitializeFromWideArgs() can now
  be called with config=NULL.

 Python always use UTF-8 on VxWorks.

Fix refleak in sysmodule.c when calling SET_SYS_FROM_STRING_BORROW.

* Incref heap-allocated types in PyObject_Init
* Add documentation and porting notes to What's New

Change "star-operator" to "* operator".

* Add _PyCoreConfig._init_main: if equals to zero,
  _Py_InitializeFromConfig() doesn't call
  _Py_InitializeMainInterpreter().
* Add interp_p parameter to _Py_InitializeFromConfig().
* pymain_init() now calls _Py_InitializeFromConfig().
* Make _Py_InitializeCore() private.

Add idlelib.pyshell alias at top; remove pyshell alias at bottom.
Remove obsolete __name__=='__main__' command.

Add test_preinit_isolated1() and test_preinit_isolated2() test_embed.

Examples of the `multiprocessing.shared_memory` module try to import `SharedMemoryManager` from `multiprocessing.shared_memory` whereas this class is defined in `multiprocessing.managers`.

* _PyCoreConfig_Write() now updates _PyRuntime.preconfig
* Remove _PyPreCmdline_Copy()
* _PyPreCmdline_Read() now accepts _PyPreConfig and _PyCoreConfig
  optional configurations.
* Rename _PyPreConfig_ReadFromArgv() to _PyPreConfig_Read(). Simplify
  the code.
* Calling _PyCoreConfig_Read() no longer adds the warning options
  twice: don't add a warning option if it's already in the list.
* Rename _PyCoreConfig_ReadFromArgv() to _PyCoreConfig_Read().
* Rename config_from_cmdline() to _PyCoreConfig_ReadFromArgv().
* Add more assertions on _PyCoreConfig in _PyCoreConfig_Read().
* Move some functions.
* Make some config functions private.

Handle memory allocation failure.

https://bugs.python.org/issue36433

Python 3.8.0a3

* Replace _PyCoreConfig.preconfig with 3 new fields in _PyCoreConfig:
  isolated, use_environment, dev_mode.
* Add _PyPreCmdline.dev_mode.
* Add _Py_PreInitializeFromPreConfigInPlace().

* Make _PyPreConfig_GetEnv(), _PyCoreConfig_GetEnv() and
  _PyCoreConfig_GetEnvDup() private
* _Py_get_env_flag() first parameter becomes "int use_environment"

* bpo-34085: Improve wording on classmethod/staticmethod

* Address comments from Éric

* Address comments from Éric