refactor: page views and app can be bound to any DOM element, not just body and document
feat(kff.App): add ability to destroy app, front controller and state handler
refactor(kff.View): enforce region 'self' to render before any other regions

Region 'self' should be rendered first, so that other regions could reference DOM elements inside the 'self' template.
fix(kff.View#renderSubview): options.element should be a plain DOM element, not a wrapper object
test: update tests to reference attribute constants in kff namespace
refactor(kff.View): kff.View constructor should not return "this"