Enable localStorage

I have 3 commits in this pull request. The first is just an update to the latest Android SDK (I hope I did it right).

The second is the most important one, which allows displaying local files inside the WebView, making it possible to make hybrid apps.

The third commit enables local DB for localStorage, which we use a lot, and may be useful for others.

Please review and merge what you feel fits your direction.

Thank you (and thank you for all your work on this plugin so far)!
Near Privman