Logging class has some global/instance confusion

[rsyring]

1. In the Flask world, init_app() is used used for manager objects that are Globally instantiated but work in the context of multiple flask apps. Since the Logging instance doesn't really do that, each Logging instance is dedicated to a single app instance, all it's init could happen in __init__().
2. But, each Logging instance is operating on the Global root logger by default, with some help from clear_keg_handlers() to make sure we don't create duplicate handlers. In essence, this is creating a last-app-loaded-wins situation, which may not be desirable.