Added a grunt build

This copies Layout.js to a dist folder, minifies and source-maps.

Gruntfile.js

@@ -0,0 +1,46 @@
+'use strict';
+
+module.exports = function(grunt) {
+
+  grunt.initConfig({
+
+    paths: {
+      distFolder: 'dist',
+      srcFolder: 'src'
+    },
+
+    clean: ['<%= paths.distFolder %>'],
+
+    copy: {
+      main: {
+        expand: true,
+        src: ['<%= paths.srcFolder %>/Layout.js'],
+        dest: '<%= paths.distFolder %>',
+        rename: function(dest, src) {
+          return dest + '/css-layout.js';
+        }
+      }
+    },
+
+    uglify: {
+      options: {
+        sourceMap: true,
+        sourceMapIncludeSources: true
+      },
+      main: {
+        files: {
+          '<%= paths.distFolder %>/css-layout.min.js': ['<%= paths.srcFolder %>/Layout.js']
+        }
+      }
+    }
+  });
+
+  grunt.loadNpmTasks('grunt-contrib-clean');
+  grunt.loadNpmTasks('grunt-contrib-copy');
+  grunt.loadNpmTasks('grunt-contrib-uglify');
+
+  grunt.registerTask('build', ['clean', 'copy', 'uglify']);
+
+  grunt.registerTask('default', ['build']);
+
+};