Merge branch 'master' into personal

* master:
  Update copyright years
  Install SLIME from MELPA
Merge branch 'personal' of github.com:eataix/prelude into personal

* 'personal' of github.com:eataix/prelude:
  [Close #547] Removed ack-and-a-half from prelude
  [Fix #623] Restored kill-region defadvice
  [Fix #753] Add a note for helm-M-x
  [Fix #756] Added helm-ag to auto install list
  elixir module
  Update default opam commands to newest syntax
  Setup the new flycheck-ocaml syntax checker
  helm-every-where takes responsibility for buffers-list