conditions in the PyOS_vsnprintf C API function. CVE-2008-3144.

Added checks for integer overflows, contributed by Google. Some are
only available if asserts are left in the code, in cases where they
can't be triggered from Python code.

problems:
52448, 52468, 52472, 52475, 52646, 52797, 52802, 52863, 52999, 53001,
53101, 53371, 53373, 53383, 53384, 53736, 53812, 53921, 55578, 55580,
55581, 55772, 55775, 56557, 57093, 57094, 58630, 60114

SF patch #1630975: Fix crash when replacing sys.stdout in sitecustomize

When running the interpreter in an environment that would cause it to set
stdout/stderr/stdin's encoding, having a sitecustomize that would replace
them with something other than PyFile objects would crash the interpreter.
Fix it by simply ignoring the encoding-setting for non-files.

This could do with a test, but I can think of no maintainable and portable
way to test this bug, short of adding a sitecustomize.py to the buildsystem
and have it always run with it (hmmm....)

the need for the out-of-tree universal binary support that was used to build
the 2.4.3 installer.

Missing here relative to that tree are some changes to IDLE, IMHO those patches
aren't appropriate for the 2.4 branch and users are better of using 2.5's IDLE.

Fix #132 from Coverity, retval could have been derefed
if a continue inside a try failed.

 this code is only used if WITHOUT_COMPLEX is *not* defined, which is the
 common case for Python builds.]

This code is actually not used unless WITHOUT_COMPLEX is defined.
However, there was no error checking that PyFloat_FromDouble returned
a valid pointer.  I believe this change is correct as it seemed
to follow other code in the area.

Klocwork # 292.