Set a url base for client urls

In order to support packaged apps (phonegap/chrome apps) the client has to know the domain to call to get to the api. This value can be set in initialize in your App subclass as it only affects the client.
Setting to force rendering on first route

If the web app has been packaged and is loaded without a server-side render then we need to be able to force the initial route to cause a render. To minimise the changes this is executed as a property set on the ClientRouter from .start() in your App subclass.