fix Cython installation, make compilation obligatory (unless explicitly disabled) and abort the installation if the compilation fails

--HG--
rename : Cython/Includes/python.pxd => Cython/Includes/Deprecated/python.pxd
rename : Cython/Includes/python2.5.pxd => Cython/Includes/Deprecated/python2.5.pxd
rename : Cython/Includes/python_bool.pxd => Cython/Includes/Deprecated/python_bool.pxd
rename : Cython/Includes/python_buffer.pxd => Cython/Includes/Deprecated/python_buffer.pxd
rename : Cython/Includes/python_bytes.pxd => Cython/Includes/Deprecated/python_bytes.pxd
rename : Cython/Includes/python_cobject.pxd => Cython/Includes/Deprecated/python_cobject.pxd
rename : Cython/Includes/python_complex.pxd => Cython/Includes/Deprecated/python_complex.pxd
rename : Cython/Includes/python_dict.pxd => Cython/Includes/Deprecated/python_dict.pxd
rename : Cython/Includes/python_exc.pxd => Cython/Includes/Deprecated/python_exc.pxd
rename : Cython/Includes/python_float.pxd => Cython/Includes/Deprecated/python_float.pxd
rename : Cython/Includes/python_function.pxd => Cython/Includes/Deprecated/python_function.pxd
rename : Cython/Includes/python_getargs.pxd => Cython/Includes/Deprecated/python_getargs.pxd
rename : Cython/Includes/python_instance.pxd => Cython/Includes/Deprecated/python_instance.pxd
rename : Cython/Includes/python_int.pxd => Cython/Includes/Deprecated/python_int.pxd
rename : Cython/Includes/python_iterator.pxd => Cython/Includes/Deprecated/python_iterator.pxd
rename : Cython/Includes/python_list.pxd => Cython/Includes/Deprecated/python_list.pxd
rename : Cython/Includes/python_long.pxd => Cython/Includes/Deprecated/python_long.pxd
rename : Cython/Includes/python_mapping.pxd => Cython/Includes/Deprecated/python_mapping.pxd
rename : Cython/Includes/python_mem.pxd => Cython/Includes/Deprecated/python_mem.pxd
rename : Cython/Includes/python_method.pxd => Cython/Includes/Deprecated/python_method.pxd
rename : Cython/Includes/python_module.pxd => Cython/Includes/Deprecated/python_module.pxd
rename : Cython/Includes/python_number.pxd => Cython/Includes/Deprecated/python_number.pxd
rename : Cython/Includes/python_object.pxd => Cython/Includes/Deprecated/python_object.pxd
rename : Cython/Includes/python_oldbuffer.pxd => Cython/Includes/Deprecated/python_oldbuffer.pxd
rename : Cython/Includes/python_pycapsule.pxd => Cython/Includes/Deprecated/python_pycapsule.pxd
rename : Cython/Includes/python_ref.pxd => Cython/Includes/Deprecated/python_ref.pxd
rename : Cython/Includes/python_sequence.pxd => Cython/Includes/Deprecated/python_sequence.pxd
rename : Cython/Includes/python_set.pxd => Cython/Includes/Deprecated/python_set.pxd
rename : Cython/Includes/python_string.pxd => Cython/Includes/Deprecated/python_string.pxd
rename : Cython/Includes/python_tuple.pxd => Cython/Includes/Deprecated/python_tuple.pxd
rename : Cython/Includes/python_type.pxd => Cython/Includes/Deprecated/python_type.pxd
rename : Cython/Includes/python_unicode.pxd => Cython/Includes/Deprecated/python_unicode.pxd
rename : Cython/Includes/python_version.pxd => Cython/Includes/Deprecated/python_version.pxd
rename : Cython/Includes/python_weakref.pxd => Cython/Includes/Deprecated/python_weakref.pxd
rename : Cython/Includes/stdio.pxd => Cython/Includes/Deprecated/stdio.pxd
rename : Cython/Includes/stdlib.pxd => Cython/Includes/Deprecated/stdlib.pxd
rename : Cython/Includes/stl.pxd => Cython/Includes/Deprecated/stl.pxd

format_map['Z'] => format_map['z'] to make room for a new Z=>Py_ssize_t*.
Also update existing uses of Z in TypeSlots.py and Builtin.py and delete
no longer needed "get"-prefixed versions of readbufferproc & friends.