Fix HatenaBookmark ICON

* Add favicon directory to skin
* Add hatenabookmark.png to favicon

via http://www.hatena.com/images/favicon/bookmark.png
    https://github.com/polygonplanet/tombloo/commit/842d36ab5eef1e37ea0fcc8c99dc8006d34fc4be

Thanks, polygonplanet!
Update Instapaper ICON

* Move Instapaper icon to favicon

via http://www.instapaper.com/favicon.png
Icons in Preference's Services should be 16x16 size

* Fix Pocket icon size