errors of _testcapimodule.c with older versions of gcc.

Fix regression of changeset 7c6e3358221a on GCC < 4.4. The _socket module
cannot be compiled on "x86 FreeBSD 7.2 3.x" buildbot anymore.

The code module was using a private function from traceback in order to skip a
frame - used the direct interface to do that instead,

The decimal module suffered minor fallout from formatting changes ('None' as a
value is now not printed by traceback, the same as None was not before).

The cgitb module was passing a bogus exception type (type.__name__) into
format_exception, which uncovered that format_exception and print_exception had
been ignoring the etype for some time, so the compatibility thunk to the new
code now does the same thing.

Provide a way to seed the linecache for a PEP-302 module without actually
loading the code.

Provide a new object API for traceback, including the ability to not lookup
lines at all until the traceback is actually rendered, without any trace of the
original objects being kept alive.

Issue #23576: Avoid stalling in SSL reads when EOF has been reached in the SSL layer but the underlying connection hasn't been closed.

Issue #23576: Avoid stalling in SSL reads when EOF has been reached in the SSL layer but the underlying connection hasn't been closed.

Fix handling of EINTR: don't return None if PyErr_CheckSignals() raised an
exception.

Initialize also the length outside the loop to only initialize it once.