Nav somewhat working. Fleshed out Gib architecture.

* Nav still having issues, but may have to work around it due to Xamarin
Forms problems. Thus, I started on the GibPage with GibView lifecycle,
which basically will be a page with a Gib button that gets new views.
This is better than navigation anyway, as I would not want most of the
pages in memory (it's forward-only philosophy).
* Added GibView/Model/Base, etc.
* Fleshed out Gib container page.
* Tweaked Log singleton (minor).