Download html bundle to update the content

[flegare]

The app rely on html content for "editorial" content. Initially we provide a bundle included in the app. The app unpack the bundle on external storage and depending on the section of the app we point a webview on the content.

The synch process to grab the new bundle rely on a REST service that show the what is the most recent version. If the version is different from the local version the app should download the bundle (could be kind to ask user if it's ok to download the bundle using 3G)

Once the file is downloaded, the part to unpack the bundle is already done.