Android: Always Show All Feeds

This is a fix for issue #150 (un-foldered feeds never showing up) and the more general issues with the android client not always showing all current folders and feeds.

Included are not only the bugfixes but a great deal of refactoring, simplification, and removal of antipatterns that was necessary for me to identify root causes in the first place, let alone fix them.

I've used this build as my daily driver for most of the week, but we should absolutely test this on a variety of devices and exercise as much functionality as possible before calling it a release candidate.