use wrappers on all platforms, to make this as consistent as possible x-
platform (in particular, make sure there's at least one \0 byte in
the output buffer).  Also document more of the truth about what these do.

getargs.c, seterror():  Three computations of remaining buffer size were
backwards, thus telling PyOS_snprintf the buffer is larger than it
actually is.  This matters a lot now that PyOS_snprintf ensures there's a
trailing \0 byte (because it didn't get the truth about the buffer size,
it was storing \0 beyond the true end of the buffer).

sysmodule.c, mywrite():  Simplify, now that PyOS_vsnprintf guarantees to
produce a \0 byte.

before 2.2b1.

functions.

are moving into the core; with these changes, it will be possible for the
exception to be raised without the weakref module ever being imported.

are overflowing and a long int operation is substituted.

add another use case to the socketmodule.

Python warning which can be catched by means of the Python warning
framework.

It also adds two new APIs which hopefully make it easier for Python
to switch to buffer overflow safe [v]snprintf() APIs for error
reporting et al. The two new APIs are PyOS_snprintf() and
PyOS_vsnprintf() and work just like the standard ones in many
C libs. On platforms which have snprintf(), the native APIs are used,
on all other an emulation with snprintf() tries to do its best.

new slot tp_iter in type object, plus new flag Py_TPFLAGS_HAVE_ITER
new C API PyObject_GetIter(), calls tp_iter
new builtin iter(), with two forms: iter(obj), and iter(function, sentinel)
new internal object types iterobject and calliterobject
new exception StopIteration
new opcodes for "for" loops, GET_ITER and FOR_ITER (also supported by dis.py)
new magic number for .pyc files
new special method for instances: __iter__() returns an iterator
iteration over dictionaries: "for x in dict" iterates over the keys
iteration over files: "for x in file" iterates over lines

TODO:

documentation
test suite
decide whether to use a different way to spell iter(function, sentinal)
decide whether "for key in dict" is a good idea
use iterators in map/filter/reduce, min/max, and elsewhere (in/not in?)
speed tuning (make next() a slot tp_next???)

for errors raised in future.c.

Move some helper functions from compile.c to errors.c and make them
API functions: PyErr_SyntaxLocation() and PyErr_ProgramText().

etc.) and the PyErr_Warn() function.

This should match the situation in the 1.6b1 tree.

add sanity check to gc: if an exception occurs during GC, call
PyErr_WriteUnraisable and then call Py_FatalEror.

filename and line number of the call site to allow esier debugging.

This closes SourceForge patch #101214.

Introduce a new builtin exception, UnboundLocalError, raised when ceval.c
tries to retrieve or delete a local name that isn't bound to a value.
Currently raises NameError, which makes this behavior a FAQ since the same
error is raised for "missing" global names too:  when the user has a global
of the same name as the unbound local, NameError makes no sense to them.
Even in the absence of shadowing, knowing whether a bogus name is local or
global is a real aid to quick understanding.

Example:

D:\src\PCbuild>type local.py
x = 42

def f():
    print x
    x = 13
    return x

f()

D:\src\PCbuild>python local.py
Traceback (innermost last):
  File "local.py", line 8, in ?
    f()
  File "local.py", line 4, in f
    print x
UnboundLocalError: x

D:\src\PCbuild>

Note that UnboundLocalError is a subclass of NameError, for compatibility
with existing class-exception code that may be trying to catch this as a
NameError.  Unfortunately, I see no way to make this wholly compatible
with -X (see comments in bltinmodule.c):  under -X, [UnboundLocalError
is an alias for NameError --GvR].

[The ceval.c patch differs slightly from the second version that Tim
submitted; I decided not to raise UnboundLocalError for DELETE_NAME,
only for DELETE_LOCAL.  DELETE_NAME is only generated at the module
level, and since at that level a NameError is raised for referencing
an undefined name, it should also be raised for deleting one.]

New function: PyErr_SetFromErrnoWithFilename(PyObject* char*)

PyExc_NumberError, and PyExc_LookupError.  Also added extern for
pre-instantiated exception instance PyExc_MemoryErrorInst.

Removed extern of obsolete exception PyExc_AccessError.

- int PyErr_GivenExceptionMatches(obj1, obj2)

  Returns 1 if obj1 and obj2 are the same object, or if obj1 is an
  instance of type obj2, or of a class derived from obj2

- int PyErr_ExceptionMatches(obj)

  Higher level wrapper around PyErr_GivenExceptionMatches() which uses
  PyErr_Occurred() as obj1.  This will be the more commonly called
  function.

- void PyErr_NormalizeException(typeptr, valptr, tbptr)

  Normalizes exceptions, and places the normalized values in the
  arguments.  If type is not a class, this does nothing.  If type is a
  class, then it makes sure that value is an instance of the class by:

  1. if instance is of the type, or a class derived from type, it does
     nothing.

  2. otherwise it instantiates the class, using the value as an
     argument.  If value is None, it uses an empty arg tuple, and if
     the value is a tuple, it uses just that.

though the checkin message failed to note that).

New file pyfpe.h, new exception FloatingPointError.

use the new names exclusively, and the linker will see the new names.
Files that import "Python.h" also only see the new names.  Files that
import "allobjects.h" will continue to be able to use the old names,
due to the inclusion (in allobjects.h) of "rename2.h".

object.h: made sizes and refcnts signed ints.
stringobject.h: make getstrsize() signed int.
methodobject.h: add METH_VARARGS and METH_FREENAME flag bit definitions.