bibclean 2.16 (new formula)

* Build failed with superenv, hence included `env :std`.
* `ENV.deparallelize` was also necessary.
* Two `inreplace` statements insert `mkdir` statements needed on MacOS.
* One `inreplace` statement fixes the `mandir` variable in `Makefile`,
since it is not properly defined by autoconfig despite the `--mandir`
parameter passed to `./configure`.
You can actually do this with `bin.env_script_all_files`; I should have mentioned that earlier. It will write a wrapper script for you too. See `ansible.rb` for an example.