#1 link errors when building the python module

[Stephane Grabli]

> cd src/swig
> make -f Makefile.cygwin
[...]
ModuleWrapper.o(.text+0x1a8b1):ModuleWrapper.cpp:
undefined reference to `_PyTuple_GetItem'
ModuleWrapper.o(.text+0x1a8fa):ModuleWrapper.cpp:
undefined reference to `_PyErr_Clear'
ModuleWrapper.o(.text+0x1a944):ModuleWrapper.cpp:
undefined reference to `_PyErr_Clear'
ModuleWrapper.o(.text+0x1a9ad):ModuleWrapper.cpp:
undefined reference to `_PyErr_Clear'
ModuleWrapper.o(.text+0x1a9ec):ModuleWrapper.cpp:
undefined reference to `__imp___Py_NotImplementedStruct'
ModuleWrapper.o(.text+0x1a9f3):ModuleWrapper.cpp:
undefined reference to `__imp___Py_NotImplementedStruct'
[...]