Remove obsolete FAQ.

Doc/faq/extending.rst

@@ -447,34 +447,3 @@ In Python 2.2, you can inherit from built-in classes such as :class:`int`,
 The Boost Python Library (BPL, http://www.boost.org/libs/python/doc/index.html)
 provides a way of doing this from C++ (i.e. you can inherit from an extension
 class written in C++ using the BPL).
-
-
-When importing module X, why do I get "undefined symbol: PyUnicodeUCS2*"?
--------------------------------------------------------------------------
-
-You are using a version of Python that uses a 4-byte representation for Unicode
-characters, but some C extension module you are importing was compiled using a
-Python that uses a 2-byte representation for Unicode characters (the default).
-
-If instead the name of the undefined symbol starts with ``PyUnicodeUCS4``, the
-problem is the reverse: Python was built using 2-byte Unicode characters, and
-the extension module was compiled using a Python with 4-byte Unicode characters.
-
-This can easily occur when using pre-built extension packages.  RedHat Linux
-7.x, in particular, provided a "python2" binary that is compiled with 4-byte
-Unicode.  This only causes the link failure if the extension uses any of the
-``PyUnicode_*()`` functions.  It is also a problem if an extension uses any of
-the Unicode-related format specifiers for :c:func:`Py_BuildValue` (or similar) or
-parameter specifications for :c:func:`PyArg_ParseTuple`.
-
-You can check the size of the Unicode character a Python interpreter is using by
-checking the value of sys.maxunicode:
-
-   >>> import sys
-   >>> if sys.maxunicode > 65535:
-   ...     print('UCS4 build')
-   ... else:
-   ...     print('UCS2 build')
-
-The only way to solve this problem is to use extension modules compiled with a
-Python binary built using the same size for Unicode characters.