Fix compatibility with msvc < 1400

make SwitchTransform always generate a 'default' clause to silence C compiler warnings about unmatched enum values

simplify search for duplicate values in SwitchTransform and make it safer for unexpected value nodes

Visual Studio .NET 2003, used by Python 2.5 32 bit, does not support the '__restrict' keyword.

Conflicts:
	CHANGES.rst

int -> Py_ssize_t in cpython pxd files

--HG--
extra : rebase_source : 6494c60e7f79a9cc85fe72a7adf325557f6de2be

remove 'from datetime cimport *' line from cpython/__init__.pxd as it refers to a separate module, not the core C-API

--HG--
extra : rebase_source : bafa0a661abe97868fe254b3ce2b5e63b8654990

remove 'from datetime cimport *' line from cpython/__init__.pxd as it refers to a separate module, not the core C-API

--HG--
extra : rebase_source : bafa0a661abe97868fe254b3ce2b5e63b8654990

--HG--
extra : rebase_source : 6494c60e7f79a9cc85fe72a7adf325557f6de2be

This reverts commit 12d7dbb3.