scripts/make-release: print out shortlog for inclusion in release announcements

The revset should generate the correct list compared with the last tagged
release on the stable branch.

The same revset should be used as a basis for release notes.

scripts/make-release

@@ -52,6 +52,9 b" diff -u <((hg mani | grep -v '^\\.hg') | "
 echo "Verify docs build"
 python2 setup.py build_sphinx # the results are not actually used, but we want to make sure it builds
 
+echo "Shortlog for inclusion in the release announcement"
+scripts/shortlog.py "only('.', branch('stable') & tagged() & public() & not '.')"
+
 cat - << EOT
 
 Now, make sure