change the grunt config for the issue Stuk#80

This commit updates the grunt configuration to ensure that the license
comment (starting with /*! for the minifiers) makes its way to the final
dist files.

Gruntfile.js

@@ -82,14 +82,19 @@ module.exports = function(grunt) {
         },
         options: {
           standalone: 'JSZip',
-          ignore:['./lib/nodeBuffer.js','./lib/nodeBufferReader']
+          ignore:['./lib/nodeBuffer.js','./lib/nodeBufferReader'],
+          postBundleCB: function(err, src, done) {
+            var license = require('fs').readFileSync('lib/license_header.js');
+            done(err, license + src);
+          }
         }
       }
     },
     uglify: {
       options: {
         report: 'gzip',
-        mangle: true
+        mangle: true,
+        preserveComments: 'some'
       },
       all: {
         src: 'dist/jszip.js',

lib/index.js

@@ -1,24 +1,4 @@
 'use strict';
-/*!
-
-JSZip - A Javascript class for generating and reading zip files
-<http://stuartk.com/jszip>
-
-(c) 2009-2012 Stuart Knightley <stuart [at] stuartk.com>
-Dual licenced under the MIT license or GPLv3. See https://raw.github.com/Stuk/jszip/master/LICENSE.markdown.
-*/
-/**
-Usage:
-   zip = new JSZip();
-   zip.file("hello.txt", "Hello, World!").file("tempfile", "nothing");
-   zip.folder("images").file("smile.gif", base64Data, {base64: true});
-   zip.file("Xmas.txt", "Ho ho ho !", {date : new Date("December 25, 2007 00:00:01")});
-   zip.remove("tempfile");
-
-   base64zip = zip.generate();
-
-**/
-
 /**
  * Representation a of zip file in js
  * @constructor

lib/license_header.js

@@ -0,0 +1,19 @@
+/*!
+
+JSZip - A Javascript class for generating and reading zip files
+<http://stuartk.com/jszip>
+
+(c) 2009-2012 Stuart Knightley <stuart [at] stuartk.com>
+Dual licenced under the MIT license or GPLv3. See https://raw.github.com/Stuk/jszip/master/LICENSE.markdown.
+*/
+/**
+Usage:
+   zip = new JSZip();
+   zip.file("hello.txt", "Hello, World!").file("tempfile", "nothing");
+   zip.folder("images").file("smile.gif", base64Data, {base64: true});
+   zip.file("Xmas.txt", "Ho ho ho !", {date : new Date("December 25, 2007 00:00:01")});
+   zip.remove("tempfile");
+
+   base64zip = zip.generate();
+
+**/