Improving the comments for the app icon setting.

There is a lot of confusion over what is the right way to set app icons. I myself struggled with this setting because the default icons generated by phonegap are also named "icon.png". When I placed an `icon.png` inside `img` folder, it didn't work. It's important to make it explicit in the documentation that the setting is taken relative the `config.xml` location.
Merge pull request #149 from manuganji/patch-1

[#149] Improving the comments for the app icon setting.
[doc] Update LICENSE copyright date.
[www] Update config.xml to match the phonegap-app-hello-world.
[www] Update index.html to match phonegap-app-hello-world.
[www] Add meta tag msapplication-tap-highlight from cordova-app-hello-world.
[www] Update www/js/index.js from cordova-app-hello-world.
[doc] Add NOTICE.
[www] Add Adobe copyright to www/index.html.
[www] Use cordova.js for closer compliance with Apache Cordova.
[doc] Update README.md
[doc] Update README.md formatting.
[doc] Update README.md with additional clarification.
Version 3.5.0