#1629: Renamed Py_Size, Py_Type and Py_Refcnt to Py_SIZE, Py_TYPE and Py_REFCNT. Macros for b/w compatibility are available.

backwards compatibility. Add Py_Refcnt, Py_Type, Py_Size, and
PyVarObject_HEAD_INIT.

In C++, it's an error to pass a string literal to a char* function
without a const_cast().  Rather than require every C++ extension
module to put a cast around string literals, fix the API to state the
const-ness.

I focused on parts of the API where people usually pass literals:
PyArg_ParseTuple() and friends, Py_BuildValue(), PyMethodDef, the type
slots, etc.  Predictably, there were a large set of functions that
needed to be fixed as a result of these changes.  The most pervasive
change was to make the keyword args list passed to
PyArg_ParseTupleAndKewords() to be a const char *kwlist[].

One cast was required as a result of the changes:  A type object
mallocs the memory for its tp_doc slot and later frees it.
PyTypeObject says that tp_doc is const char *; but if the type was
created by type_new(), we know it is safe to cast to char *.

Thanks to Skip Montanaro and Kalle Svensson for the patches.

Preliminary support.  What's here works, but needs fine-tuning.

This should match the situation in the 1.6b1 tree.

clear_carefully() used to do in import.c.  Differences: leave only
__builtins__ alone in the 2nd pass; and don't clear the dictionary (on
the theory that as long as there are references left to the
dictionary, those might be destructors that might expect __builtins__
to be alive when they run; and __builtins__ can't normally be part of
a cycle).

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.

* Makefile: change location of FORMS library.
* posixmodule.c: turn #if 0 into #ifdef MSDOS (stuff in unistd.h or not)
* Almost all .h files: added CPP magic to avoid duplicate inclusions and
  to support inclusion from C++.

* Stubs for faster implementation of local variables (not yet finished)
* Added function name to code object.  Print it for code and function
  objects.  THIS MAKES THE .PYC FILE FORMAT INCOMPATIBLE (the version
  number has changed accordingly)
* Print address of self for built-in methods
* New internal functions getattro and setattro (getattr/setattr with
  string object arg)
* Replaced "dictobject" with more powerful "mappingobject"
* New per-type functio tp_hash to implement arbitrary object hashing,
  and hashobject() to interface to it
* Added built-in functions hash(v) and hasattr(v, 'name')
* classobject: made some functions static that accidentally weren't;
  added __hash__ special instance method to implement hash()
* Added proper comparison for built-in methods and functions