of issue #3720.

exception afterwards (for a subsequent parameter), the user code will
not call PyBuffer_Release() and memory will leak.

Reviewed by Amaury Forgeot d'Arc.

match Python 2.5 speed despite the __instancecheck__ / __subclasscheck__
mechanism. In the process, fix a bug where isinstance() and issubclass(),
when given a tuple of classes as second argument, were looking up
__instancecheck__ / __subclasscheck__ on the tuple rather than on each
type object.

Reviewed by Benjamin Peterson and Raymond Hettinger.

affects some buildbots.

R=Brett
TESTED=./python -E -tt ./Lib/test/regrtest.py test_multiprocessing

Add some test coverage to this code.  More tests should be added (TODO added).

R=Brett
TESTED=./python -E -tt ./Lib/test/regrtest.py test_multiprocessing

Clarify that some attributes/methods are listed somewhat separately because they are not part of the threading API.

TESTED=./python -E -tt ./Lib/test/regrtest.py test_fileio
R (approach from bug)=Amaury and Benjamin

Reviewer: Brett Cannon

 * crashes on memory allocation failure found with failmalloc
 * memory leaks found with valgrind
 * compiler warnings in opt mode which would lead to invalid memory reads
 * problem using wrong name in decimal module reported by pychecker

Update the valgrind suppressions file with new leaks that are small/one-time
leaks we don't care about (ie, they are too hard to fix).

TBR=barry
TESTED=./python -E -tt ./Lib/test/regrtest.py -uall (both debug and opt modes)
  in opt mode:
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py -uall,-bsddb,-compiler \
                        -x test_logging test_ssl test_multiprocessing
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py test_multiprocessing
  for i in `seq 1 4000` ; do
    LD_PRELOAD=~/local/lib/libfailmalloc.so FAILMALLOC_INTERVAL=$i \
        ./python -c pass
  done

At least some of these fixes should probably be backported to 2.5.

Author: Victor Stinner
Reviewer: Benjamin Peterson

Reviewer: Christian Heimes

Modules/_collectionsmodule.c:674: warning: format '%i' expects type 'int', but argument 2 has type 'Py_ssize_t'
Reviewed by Benjamin Peterson

Modules/_sqlite/row.c:187: warning: suggest parentheses around && within ||
Reviewed by Benjamin Peterson

Objects/stringlib/find.h:97: warning: 'stringlib_contains_obj' defined but not used
Reviewed by Benjamin Peterson