add grunt task for running jscs checks

usage: "grunt jscs"
https://github.com/jscs-dev/grunt-jscs/

.gitignore

@@ -8,3 +8,5 @@ vendor/
 # test coverage
 tests/clover.xml
 
+# Node.js modules
+node_modules/
\ No newline at end of file

.jscsrc

@@ -24,7 +24,7 @@
         "js/backbone.marionette.js",
         "js/jquery.autosize.js",
         "js/jquery.storageapi.js",
-        "js/jquery.visibility.js"
+        "js/jquery-visibility.js"
     ],
 
     "jsDoc": {

Gruntfile.js

+/* global module */
+
+/**
+ * ownCloud - Mail
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later. See the COPYING file.
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @copyright Christoph Wurst 2015
+ */
+module.exports = function (grunt) {
+	// Project configuration.
+	grunt.initConfig({
+		jscs: {
+        		src: 'js/*.js',
+			options: {
+				config: '.jscsrc',
+				verbose: true
+			}
+		}
+	});
+
+	// jscs
+	grunt.loadNpmTasks('grunt-jscs');
+
+	// Default task
+	grunt.registerTask('default', ['grunt-jscs']);
+};

package.json

@@ -24,6 +24,8 @@
   },
   "homepage": "https://github.com/owncloud/mail",
   "devDependencies": {
+    "grunt-jscs": "^1.8.0",
+    "jscs-jsdoc": "^1.0.1",
     "jshint": "^2.7.0",
     "jsxhint": "^0.14.0"
   }