Using the standard (type class based) transitivity tactic for more contr...

...olable proof terms. As discussed in #454.
You should not be changing this.  You probably ran `git commit -a` without running `git submodule sync` or `git submodule update`.  To fix, run `cd etc/coq-scripts && git remote update && git checkout 6c4889941809dc83172755b576b5a9239c0571e6 && cd ../../ && git add etc/coq-scripts && git commit --amend`