Introduced gc_list_move(), which captures the common gc_list_remove() +
gc_list_append() sequence.  In fact, no uses of gc_list_append() remained
(they were all in a gc_list_move() sequence), so commented that one out.

gc_list_merge():  assert that `from` != `to`; that was an implicit
precondition, now verified in a debug build.

Others:  added comments about their purpose.

pass over the unreachable weakrefs-with-callbacks to unreachable objects.

Rewrite rmtree again, this time without os.walk(). Error handling had been
broken since Python 2.3, and the os.walk() version inherited this.

In cyclic gc, clear weakrefs to unreachable objects before allowing any
Python code (weakref callbacks or __del__ methods) to run.

This is a critical bugfix, affecting all versions of Python since weakrefs
were introduced.  I'll backport to 2.3.

* Use simpler, faster two pass algorithm for markblocks().
* Free the blocks variable if not NULL and exiting without change.
* Verify that the rest of the compiler has not set an exception.
* Make the test for tuple of constants less restrictive.
* Embellish the comment for chained conditional jumps.

- always include a space after the "#" that starts a comment
- easier to read imports

exposed in header files.  Fixed a few comments in these headers.

As we might have expected, writing down invariants systematically exposed a
(minor) bug.  In this case, function objects have a writeable func_code
attribute, which could be set to code objects with the wrong number of
free variables.  Calling the resulting function segfaulted the interpreter.
Added a corresponding test.

of the year, and day of the week.  Was not taking into consideration properly
the issue of when %U is used for the week of the year but the year starts on
Monday.

Closes bug #1045381 again.

(Contributed by Facundo Batista.)

Code simplification by eliminating the unnecessary and error-prone
convolutions for the previously weird sign convention in _WorkRep().
Makes the code more understandable, more reliable, and a bit faster.

The underlying bug still exists, but also existed in 2.3.4:
import.c's load_source_module() returns NULL if
PyOS_GetLastModificationTime() returns -1, but
PyOS_GetLastModificationTime() doesn't set any exception when it returns
-1, and neither does load_source_module() when it gets back -1.  This
leads to "SystemError: NULL result without error in PyObject_Call"
on an import that fails in this way.

    Python software
to
    this software ("Python")

- Added a chunk of plist data as generated by Cocoa's NSDictionary and
  verify we output the same (including formatting)
- Changed the "literal" plist code to match the raw test data

version of base64.encodestring() so I could control the line length of the
base64 output.

(Submitted by James William Pye, Patch revised by Jiwon Seo)

And add an optional argument 'filename' to linecache.checkcache()
to enable checking caches per-file.

Peepholer could be fooled into misidentifying a tuple_of_constants.
Added code to count consecutive occurrences of LOAD_CONST.
Use the count to weed out the misidentified cases.
Added a unittest.

  a) the functionality depended on PyXML before and b) hardly worked to
  begin with.
- Instead, output and require upon input datetime.datetime objects.

  writePlistToString()
- use these two in the resource functions.
- Tweaked module doc string.

_PyString_Resize() readied strings for mutation but did not invalidate
the cached hash value.

the dict(**kwargs) feature.

- fix a minor formatting nit that affected the typeset version