Set data pointer to NULL after an error; this keeps the mmap_dealloc() function from trying to do msync(-1);munmap(-1).
2.3 bugfix candidate, but this bug isn't critical enough that the fix has to go into 2.3.4

(Code contributed by Jiwon Seo.)

The documentation portion of the patch is being re-worked and will be
checked-in soon.  Likewise, PEP 289 will be updated to reflect Guido's
rationale for the design decisions on binding behavior (as described in
in his patch comments and in discussions on python-dev).

The test file, test_genexps.py, is written in doctest format and is
meant to exercise all aspects of the the patch.  Further additions are
welcome from everyone.  Please stress test this new feature as much as
possible before the alpha release.

- read() method returns a list of files parsed successfully
- add tests, documentation
(closes SF patch #677651)

- DuplicateSectionError is only raised by add_section()
(closes SF bug #830449)

- don't allow setting options to non-string values; raise TypeError
  when the value is set, instead of raising an arbitrary exception
  later (such as when string interpolation is performed)
- add tests, documentation
(closes SF bug #810843)

- ensure that option names in interpolations are handled by
  self.optionxform in the same way that other references to option
  names
- add tests, documentation
(closes SF bug #857881, patch #865455)

converting it into assertRaises() form.  Restored the 2.3 code, and
explained why assertRaises() cannot be used instead.

still 7-bit.

parser must recognize outer boundaries in inner parts.  So cruise through the
EOF stack backwards testing each predicate against the current line.

There's still some discussion about whether this is (always) the best thing to
do.  Anthony would rather parse these messages as if the outer boundaries were
ignored.  I think that's counter to the RFC, but might be practically more
useful.  Can you say behavior flag?  (ug).

Two evil samples from Anthony's MIME torture tests.

same boundary as the outer part.

separating boundary for an outer part inside an inner part.

optimization for short input; beef up tests for fix_sentence_endings
feature.

Minor wording fix.

same method that implements __setitem__ also implements __delitem__.
Also, there were several good use cases (removing items from a queue
and implementing Forth style stack ops).

(closes SF patch #870287)

(closes SF patch #952047)

(closes SF bug #952212)

message/delivery-status clause, and genericize it to handle all (other)
message/* content types.  This lets us correctly parse 2 more of Anthony's
MIME torture tests (specifically, the message/external-body examples).

copyright years.