Added NEWS.txt that provides a synopsis of the change since the last version. Integrated NEWS.txt in documentation.
diff --git a/doxybuild.py b/doxybuild.py
index 0a2a6c7..0a31aae 100644
--- a/doxybuild.py
+++ b/doxybuild.py
@@ -127,6 +127,7 @@
         tarball_sources = [
             output_dir,
             'README.txt',
+            'NEWS.txt',
             'version'
             ]
         tarball_basedir = os.path.join( output_dir, html_output_dirname )