Fix bad condition in WebApp._onNavigationRequest

Silly error:

approved = this.allowedURI ? true : this.allowedURI.test(request.url);

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Handle WebKit.PolicyDecisionType.NEW_WINDOW_ACTION

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Link advanced articles in tutorial/guide

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>