Update manifest

MANIFEST.in

 include MANIFEST.in README.txt INSTALL.txt CHANGES.txt ToDo.txt USAGE.txt
+include CHANGES_pyrex.txt COPYING.txt LICENSE.txt Makefile
 recursive-include .hg *
 recursive-include Cython/.hg *
 include setup.py
@@ -6,6 +7,16 @@ include bin/cython
 include cython.py
 include Cython/Compiler/Lexicon.pickle
 include Doc/*
-include Demos/*.p*
+include Demos/*.pyx
+include Demos/*.pxd
+include Demos/Setup.py
 include Demos/Makefile*
+include Tools/*
+recursive-include Includes *
+recursive-include tests *.pyx *.pxd *.pxi *.h
+include runtests.py
+
 include Cython/Compiler/Builtin.py
+include Cython/Mac/Makefile
+include Cython/Mac/_Filemodule_patched.c
+include Cython/Unix/*.py