Revert bogus asserts (added to the wrong place) from rev 52501.

Approved by Anthony.

Fix a bug when using the __lltrace__ opcode tracer, and a problem sith signed chars in frameobject.c which can occur with opcodes > 127

(EIO can occur on Linux) or there's no more data to read.  Without this,
test_pty.py can hang on the waitpid() because the child is blocking on the
stdout write.  This will definitely happen on Mac OS X and could potentially
happen on other platforms.  See the comment for details.

  Patch taken from http://bugs.debian.org/416934.

SF #1685563, MSVCCompiler creates redundant and long PATH strings

If MSVCCompiler.initialize() was called multiple times, the path
would get duplicated.  On Windows, this is a problem because the
path is limited to 4k.  There's no benefit in adding a path multiple
times, so prevent that from occuring.  We also normalize the path
before checking for duplicates so things like /a and /a/ won't both
be stored.

since the 2.5.0 release.

Backport of r54615.

returned by python-config if Python was built with --enable-shared
because that prevented the shared library from being used.
  (backport from rev. 54634)

Fix SF #1688393, sock.recvfrom(-24) crashes

Also fix some method names that were copied incorrectly (trunk fixed).

the C lib's clock() is used, but it must be divided by CLOCKS_PER_SEC
as for the POSIX implementation (thanks to #pypy).
 (backport from rev. 54606)

Python 2.5 added support for explicit relative import statements and
yield expressions, which were missing in the manual.
Also fix grammar productions that used the names from the Grammar file,
markup that broke the generated grammar.txt, and wrap some lines that
broke the pdf output.
 (backport from rev. 54559)

overflows the valid Py_ssize_t range.  Check return values of
PyMem_Malloc.

Backported from trunk.

question (well, two months too late).

The code in this patch leaves no way to give up the ownership of a
BSTR instance.

 (backport from rev. 54524)

now be unpickled.
 (backport form rev. 54492)

given to get(). It also detects when you use '&' as the last argument
and creates a BackgroundBrowser then.
 (backport -- this is a regression from 2.4 and therefore backported)

 (backport from rev. 54483)

masked by a generic one with the message "unpack non-sequence".
 (backport from rev. 54480)

Extend work on rev 52962 and 53830 eliminating redundant PyObject_Hash() calls and fixing set/dict interoperability.