Fragment factory

Use FragmentFactory to open drawers, navigators, pages or intents.
Updated logging
Removed PageStackHelper
Updated app.json to version 6

Still Needed:
Fragment caching on drawer menu items
Better handling of the back button
A native page

We could represent all four of these as a JSONObject and called it the "rootPage" and get page, title, options, etc out of it. Generalize it a bit further.