Added icons to manifest and create icons folder.

Author: victorvrv

images/icon_128.png renamed to src/browser/chrome/icons/icon_128.png

@@ -5,10 +5,15 @@
   "manifest_version": 2,
   "page_action": {
     "default_icon": {        
-      "32": "icon.png"   
+      "32": "icons/pa_icon.png"   
     },
     "default_popup": "page_action.html"
   },
+  "icons": { 
+    "16": "icons/icon_16.png",
+    "48": "icons/icon_48.png",
+   "128": "icons/icon_128.png" 
+  },
   "background": {
     "scripts": ["devtools_bundle/bg_bundle.js"]
   },