Have tuareg mode set the compile command

to utilize corebuild via opam
Improve ocaml module documentation

Add some documentation about environment assumptions, and correct some
grammar issues.
Merge pull request #724 from RadicalZephyr/ocaml

Ocaml improvements
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Improve ocaml module documentation
  Have tuareg mode set the compile command