Patch contributed by Swati Jaiswal.

Patch contributed by SilentGhost.

Patch contributed by Robert Zimmerman.

upstreams such as Cython will have to adjust.

  appearing before $() vars.

The decision is that we shouldn't remove popular APIs (however long they
are depreacted) from Python 3, while 2.7 is still around and supported.

picklability regression.  Also, as per further discussion, remove the
regressing code.

_PyObject_GetState() due to regressions observed in Cython-based projects.

_PyObject_GetState() due to regressions observed in Cython-based projects.

Patch by Марк Коренберг.