README and CHANGES were renamed. Update MANIFEST.in to include them once again...

README and CHANGES were renamed. Update MANIFEST.in to include them once again in the source distributions. Fixes #575.

MANIFEST.in

@@ -5,7 +5,7 @@ recursive-include docs *.py *.txt *.conf *.css *.css_t Makefile indexsidebar.htm
 recursive-include setuptools/_vendor *
 recursive-include pkg_resources *.py *.txt
 include *.py
-include *.txt
+include *.rst
 include MANIFEST.in
 include launcher.c
 include msvc-build-launcher.cmd