Crosswalk Project 16: Chromium 45, background_color, Widevine support

Crosswalk 16 for Android has entered the stable channel and adds the following features and changes.

• Update to Chromium 45, which includes new JavaScript language features, an improved audio experience on Android, and a large number of minor API improvements and deprecations. Read the announcement for more details.
• Crosswalk can now play back Widevine DRM-protected content (XWALK-5030)
• A new xwalk_view.background_color field can be added to the manifest.json, to specify the background color of the XWalkView
• When onReceivedLoadError occurs, a Toast notification is displayed to the user instead of a dialog (as the user cannot do anything to respond to the error)
• Presentation API on Android follows an updated W3C Spec.
• External extensions have an additional binary messaging interface for better performance when large amounts of data need to be passed to and from the extension.
• The signature of the downloaded Crosswalk APK is verified when starting the application in shared mode.
• Android support libraries (e.g. support-v4, support-v7 etc) are no longer bundled by Crosswalk and should be included explicitly if required.