Remove unneeded functions and vars

`es-mode-hook` and `es-mode-map` is automatically defined when using `define-derived-mode`.

`define-derived-mode` also sets the syntax table automatically to `es-syntax-table`.

`prog-mode` was introduced in Emacs 24. Add `fundamental-mode` as parent-mode when it is not available.


I am also working bringing the server requests into Emacs. You can see what I am thinking on d4da3a2901.