Add AuthDialog for Username/password collection
Add minimalistic RequestHandler that allows for an AuthDialog of type IAuthDialog
Change AuthDialog.xaml.cs to implement IAuthDialog
Assign RequestHandler to WebView in BrowserTabView constructor
Add Reload KeyBindings
Remove unused T oldvalue and T newValue params from OnPropertyChanged<T>
Remove unused reference
Remove non-existent class from project (was accidentally re-added to the proj file during cherry pick)
Updated as per changes to IRequestHandler (originally Cheery picked from an old WIP branch)
Temporarily implement ChangeAndNotify in AuthDialog until full MVVM changes are complete
API cleanup - move non WPF specific commands from IWpfWebBrowser to IWebBrowser
Move KeyBindings from MainView to MainWindow they weren't being captured for some reason
Set IsBrowserInitialized