Adds ocaml-fix

Fix is a simple OCaml module for computing the least solution of a system of monotone equations.

Homepage: http://gallium.inria.fr/~fpottier/fix/
Adds ocaml-pprint

Pprint is an OCaml adaptation of Wadler’s and Leijen’s prettier printer.

Homepage: http://gallium.inria.fr/~fpottier/pprint/
Adds ocaml-functory

Functory is a distributed computing library for Objective Caml which facilitates distributed execution of parallelizable computations in a seamless fashion. Further, it is
polymorphic, incorporates a robust fault-tolerant mechanism and is already being deployed in real-world applications.

Homepage: https://www.lri.fr/~filliatr/functory/
Adds mezzo

Mezzo is a programming language in the ML tradition, which places strong
emphasis on the control of aliasing and access to mutable memory.

Homepage: http://protz.github.io/mezzo/
Merge pull request #4061 from vbgl/mezzo

Adds mezzo and its dependencies
Higan: adding "profile" and "gui" building options

Also, removing builder.sh and copying everything to Nix expression.

Closes #4048