Apply modified version of Collin Winter's patch #1478788

Renames functional extension module to _functools and adds a Python
functools module so that utility functions like update_wrapper can be
added easily.
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index cf657c3..0691179 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -129,8 +129,8 @@
 % Functions, Functional, Generators and Iterators
 % XXX intro functional
 \input{libitertools}
-\input{libfunctional}
-\input{liboperator}       % from runtime - better with itertools and functional
+\input{libfunctools}
+\input{liboperator}       % from runtime - better with itertools and functools
 
 
 % =============