Notes to myself on all the steps to make for a Ninja release.

1. update src/version.cc with new version (with ".git")
2. git checkout release; git merge master
3. fix version number in src/version.cc (it will likely conflict in the above)
4. fix version in doc/manual.asciidoc
5. rebuild manual, put in place on website
6. commit, tag, push
7. construct release notes from prior notes
   credits: git shortlog -s --no-merges REV..