set the emacs mark on merlin--goto-file-and-point (#508)
set the emacs mark on merlin--goto-file-and-point (#508)

resolves #294
dra27/merlin,ocaml/merlin,dra27/merlin,rgrinberg/merlin,rgrinberg/merlin,ocaml/merlin,the-lambda-church/merlin,ocaml/merlin,the-lambda-church/merlin,rgrinberg/merlin,dra27/merlin,rgrinberg/merlin,dra27/merlin,the-lambda-church/merlin,ocaml/merlin