Fix invalid SQLite expression.

Apparently SQLite.NET doesn't support !bool, so it had to be written as
bool != true, which is supported.
Rename BaseModelsViewAdapter.

Renamed ModelsViewAdapter to BaseModelsViewAdapter as that is more like
how the classes in the Android framework are named.
Fix models view dapter item type typo.

The BaseModelsViewAdapter had a typo in the GetItemViewType method,
which made it treat every row as a loading indicator.
Fix notification on model change.

RecentTimeEntriesView global model change listener failed to notify
about changes to the underlying data, thus breaking databinding.
Fix crash related to view type values.

Android Adapter.GetItemViewType() must return integers starting from 0
(noted in the docs). As the code did not do that, it produced a very
cryptic crash.