Add MANIFEST.in for building source package.

MANIFEST.in

@@ -0,0 +1,17 @@
+#
+# Use .add_data_files and .add_data_dir methods in a appropriate
+# setup.py files to include non-python files such as documentation,
+# data, etc files to distribution. Avoid using MANIFEST.in for that.
+#
+include MANIFEST.in
+include LICENSE.txt
+include README.txt
+include TASKS.txt
+include CONTRIBUTORS.txt
+# Add documentation: we don't use add_data_dir since we do not want to include
+# this at installation, only for sdist-generated tarballs
+include doc/Makefile
+recursive-include doc/source *
+recursive-include doc/tools *
+recursive-include doc/ext *
+