emacs: Update mode file

This is a squashed commit including the following changes:
1) Update mode header
2) Clean up white-space
3) Fix free variable warning
4) Add proper file ending stuff
5) Rename to keep conventional naming scheme
6) Updates to the readme
7) Update to conform to `package-lint` criteria
8) Add license header
9) Add in-file instructions

tools/emacs/README.txt

@@ -1,6 +1,7 @@
 === Emacs Syntax Highlighting ===
 Created by Aidan Thompson 12/2010
 ===============================
+Updated by Roit Goswami Mon Jul 30 2018 
 
 The lammps.el file provided in this directory will enable syntax 
 highlighting for the lammps script syntax in emacs. The groupings
@@ -15,9 +16,40 @@ some basic syntax highlighting of strings, comments, etc.
 ============================
 (0) Create/edit the emacs init file ~/.emacs to contain:
    
-(load "~/.emacs.d/lammps")
+(load "~/.emacs.d/lammps-mode.el")
 
 This file may also be called ~/.emacs.el, or ~/.emacs.d/init.el
 
-(1) Copy lammps.el to the directory ~/.emacs.d
+(1) Copy lammps-mode.el to the directory ~/.emacs.d
 
+=Update:
+========
+
+The package may now also be installed by a MELPA style recipe, namely:
+
+```lisp
+(lammps-mode :fetcher github :repo "HaoZeke/lammps-mode")
+```
+
+For a simpler installation with `use-package` simply add:
+
+```lisp
+(use-package lammps-mode)
+```
+
+The latest version of the package will be kept in sync as a squashed update on
+the lammps repository as well.
+
+It is advisable to use the MELPA installation methods listed here:
+https://melpa.org/#/getting-started
+
+For autoloading and auto-recognizing "in.*" and "*.lmp" files add the following
+to `.emacs`:
+
+```lisp
+(autoload 'lammps-mode "lammps-mode.el" "LAMMPS mode." t)
+(setq auto-mode-alist (append auto-mode-alist
+                              '(("in\\." . lammps-mode))
+                              '(("\\.lmp\\'" . lammps-mode))
+                              ))
+```

tools/emacs/lammps-mode.el

@@ -1,7 +1,49 @@
-;; LAMMPS auto-mode
+;;; lammps-mode.el --- basic syntax highlighting for LAMMPS files
+
+;; Copyright (C) 2010-18 Aidan Thompson
+;; Copyright (C) 2018 Rohit Goswami
+
+;; Author: Aidan Thompson <athomps at sandia.gov>
+;; Maintainer: Rohit Goswami <r95g10 at gmail.com>
+;; Created: December 4, 2010
+;; Modified: July 30, 2018
+;; Version: 1.5.0
+;; Keywords: languages, faces
+;; Homepage: https://github.com/lammps/lammps/tree/master/tools/emacs
+;; Package-Requires: ((emacs "24.4"))
+
+;; This file is not part of GNU Emacs.
+
+;; This file is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; This file is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to
+;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
 ;; translation of keyword classes from tools/vim
 ;; see http://xahlee.org/emacs/elisp_syntax_coloring.html
 
+;; Put this in your .emacs file to enable autoloading of lammps-mode
+;; and auto-recognition of "in.*" and "*.lmp" files:
+;;
+;; (autoload 'lammps-mode "lammps-mode.el" "LAMMPS mode." t)
+;; (setq auto-mode-alist (append auto-mode-alist
+;;                               '(("in\\." . lammps-mode))
+;;                               '(("\\.lmp\\'" . lammps-mode))
+;;                               ))
+;;
+
+;;; Code:
  ;; define several keyword classes
 (defvar lammps-output
   '("log"
@@ -136,6 +178,8 @@
 (defvar lammps-variable-regexp
   "\\$\\({[a-zA-Z0-9_]+}\\)\\|\\$[A-Za-z]")
 
+(defvar lammps-font-lock-keywords)
+
 ;; clear memory
 (setq lammps-output nil)
 (setq lammps-read nil)
@@ -151,8 +195,7 @@
 
 ;; create the list for font-lock.
 ;; each class of keyword is given a particular face
-(setq 
+(setq lammps-font-lock-keywords
- lammps-font-lock-keywords
  `((,lammps-output-regexp . font-lock-function-name-face)
    (,lammps-read-regexp . font-lock-preprocessor-face)
    (,lammps-lattice-regexp . font-lock-type-face)
@@ -200,11 +243,11 @@
   (setq lammps-variable-regexp nil))
 
 ;; apply it to specified filename patterns
-(setq 
+(setq auto-mode-alist
- auto-mode-alist
+ (append auto-mode-alist
- (append 
-  auto-mode-alist
   '(("in\\." . lammps-mode))
   '(("\\.lmp\\'" . lammps-mode))
   ))
 
+(provide 'lammps-mode)
+;;; lammps-mode.el ends here