Replace uses of PyCF_xxx with CO_xxx.

Replace individual feature slots in PyFutureFeatures with single
bitmask ff_features.

When flags must be transfered among the three parts of the interpreter
that care about them -- the pythonrun layer, the compiler, and the
future feature parser -- can simply or (|) the definitions.

Replace individual slots in PyFutureFeatures with a single bitmask
with one field per feature.  The flags for this bitmask are the same
as the flags used in the co_flags slot of a code object.

    XXX This means we waste several bits, because they are used
    for co_flags but have no meaning for future statements.  Don't
    think this is an issue.

Remove the NESTED_SCOPES_DEFAULT define and others.  Not sure what
they were for anyway.

Remove all the PyCF_xxx flags, but define PyCF_MASK in terms of the
CO_xxx flags that are relevant for this release.

Change definition of PyCompilerFlags so that cf_flags matches
co_flags.

attribute changed again.

  problem).  inherit_slots() is split in two parts: inherit_special()
  which inherits the flags and a few very special members from the
  dominant base; inherit_slots() which inherits only regular slots,
  and is now called for each base in the MRO in turn.  These are now
  both void functions since they don't have error returns.

- Added object.__setitem__() back -- for the same reason as
  object.__new__(): a subclass of object should be able to call
  object.__new__().

- add_wrappers() was moved around to be closer to where it is used (it
  was defined together with add_methods() etc., but has nothing to do
  with these).

Depend AF_PACKET on HAVE_NETPACKET_PACKET_H.

Depend AF_PACKET on HAVE_NETPACKET_PACKET_H. Fixes #449157

PyDict_Merge(a, b, 1) is the same as PyDict_Update(a, b).
PyDict_Merge(a, b, 0) does something similar but leaves existing items
unchanged.

    libraries.  This is done by adding a .get_source_files() method,
    contributed by Rene Liebscher and slightly modified.
Remove an unused local variable spotted by PyChecker

This fixes the problem reported in bug report #438786.

informative when a child process dies with an error.

This is a variation of parts of SF patch #429611.

platforms.

This is part the response to SF patch #429611.

have it, especially on non-Unix platforms.  (MikTeX in particular does not
have it.)

This is part of the response to SF patch #429611.

Use construction-syntax for an exception to make the argument easier
to read.

   though 'licence' is still supported for backward-compatibility
   (Should I add a warning to get_licence(), or not bother?)

Also fixes an UnboundLocalError noticed by PyChecker

it possible to detect recursive calls early (as opposed to when the
stack overflows :-).

section on functions which return stack frames.

This closes SF bug #449258.

type is ready, and READYING to indicate that it is busy with the type.

A recursive call is a fatal error.

This closes SF patch #428320.

Added documentation for the new floordiv() and truediv() functions.
This is part of SF bug #449093.

Re-organized the listing of functions to get better logical grouping.

  available in java, so only use the advanced flush options if they
  are defined in the zlib module.

bug #449000, "re.sub(r'\n', ...) broke".  This was Fredrik's
suggestion -- he's on vacation and said he wouldn't be able to work on
this until next week.

of PyList_Append.

Wrap some long lines.
Remove unnecessary tuple unpack.

it has no such parameter.

This closes SF bug #449761.

Fixes the problem reported in bug #438786.

Removed all instances of Py_UCS2 from the codebase, and so also (I hope)
the last remaining reliance on the platform having an integral type
with exactly 16 bits.
PyUnicode_DecodeUTF16() and PyUnicode_EncodeUTF16() now read and write
one byte at a time.