Maybe: unify the two pointer()s and move into app

[issa-tseng]

This would really really centralize all the magic into App. The main issues standing in the way are:

1. Model bind should work without an App instance. This is the worst offender. i think this is no longer a problem?
2. The reference to this.options.app won't work the same with view subject context vs model self context.
3. Item 1 may no longer be a problem, but now the two have diverged again due to differences in how viewmodel and subject resolve.