Manage listeners from the kernel

Have the kernel directly manage event listeners. Support namespaced event names.

The kernel will use a private namespace in `branch/collection-events` to send meta events into the application using names that won't conflict with any possible application event name. Additionally, the kernel will need to have direct knowledge of event listeners in order to replicate them correctly.

This is a predecessor to `branch/collection-events`, which uses the event mechanism for the kernel to deliver meta events into the application.

@eric79 , please review.

These do need to be refactored, but it's going to require using a function generator that parses API descriptors from `api/model`. Differences between the calls, and compatibility with API changes, make each handler more different than a generic function can handle.