package daemon: Make all work with the packages asynchronous

There's now a worker thread per Root that does all the work that can
take time. Node monitoring notifications received in the main thread are
just pushed into the worker's job queue, so the application looper
remains responsive.

package daemon: Make all work with the packages asynchronous

There's now a worker thread per Root that does all the work that can
take time. Node monitoring notifications received in the main thread are
just pushed into the worker's job queue, so the application looper
remains responsive.