Install SLIME from MELPA
Update copyright years
Setup the new flycheck-ocaml syntax checker
Update default opam commands to newest syntax

Newer versions of opam don't do argument parsing of the first argument
after `opam config exec` so everything needs to be passed as separate
arguments in the shell (i.e. unquoted).
Merge pull request #754 from RadicalZephyr/ocaml-flycheck

Ocaml flycheck
Merge commit '63a63b2f00b4f794926ad6f47a763d2cc0cc7a44' into master-sujal