Adds the menhir stanza which desugars into a Rule.t with Support for:
* ocamlyacc like use
* modular parsers with --base
* passing extra flags
Also add tests and documentation.
Makes the output quieter by default and add a `--verbose` argument. Print a message when waiting for background jobs to finish only it it takes more than 0.5 seconds.
Before this commit, when there was more than one applicable
assignment, the one with the lowest number of formal predicates was
selected instead of the one with the biggest number of formal predicates