Switch BrowserViewController's designated initializer back to its superclass's.
Tidy up UIWebView-specific state restoration stuff.

Not sure what WKWebView needs in this area, but it doesn't need what UIWebView did.
KVO-observe wkwebview title
Formatting.
Switch Awful Browser to UIActivityViewController.
Tidy up other bar button items in Awful Browser.
Add 'Open in Safari' and 'Open in Chrome' activities to Awful Browser.
Migrate view models to new GRMustache version.

Need to expose the properties we're using on the underlying model object.