Grunt: Add watch task to rebuild on src changes

Fixes gh-236
Closes gh-238

Author: jzaefferer

Gruntfile.js

@@ -1,6 +1,7 @@
 module.exports = function(grunt) {
   grunt.loadNpmTasks('grunt-contrib-jshint');
   grunt.loadNpmTasks('grunt-contrib-uglify');
+  grunt.loadNpmTasks('grunt-contrib-watch');
   grunt.loadNpmTasks('grunt-git-authors');
   grunt.loadNpmTasks('grunt-jscs');
   grunt.loadNpmTasks('intern');
@@ -80,6 +81,15 @@ module.exports = function(grunt) {
         jshintrc: true
       },
       main: allFiles
+    },
+    watch: {
+      src: {
+        files: ['src/*', 'pointerevents.js'],
+        tasks: ['build', 'lint'],
+        options: {
+          spawn: false
+        }
+      }
     }
   });
 

package.json

@@ -11,7 +11,12 @@
     "type": "git",
     "url": "git://github.com/jquery/PEP.git"
   },
-  "files": ["dist/", "src/", "pointerevents.js", "samples/"],
+  "files": [
+    "dist/",
+    "src/",
+    "pointerevents.js",
+    "samples/"
+  ],
   "bugs": "https://github.com/jquery/PEP/issues",
   "license": "MIT",
   "devDependencies": {
@@ -24,6 +29,7 @@
     "grunt": "~0.4.1",
     "grunt-contrib-jshint": "0.11.2",
     "grunt-contrib-uglify": "^0.4.0",
+    "grunt-contrib-watch": "^0.6.1",
     "grunt-git-authors": "^3.0.0",
     "grunt-jscs": "1.8.0",
     "intern": "2.2.2",