inotify: server: use a common 'pollable' interface for server & repowatcher Mainly for documentation purposes: it easily explains the role of handle_event and handle_timeout, and why both server & repowatcher implement those methods.

inotify: process all inotify events in one batch When several inotify events happen, we don't have to process each event separately, calling everytime repowatcher.read_events() to fetch events from the underlying watcher: it is sufficient to call once read_events, to fetch all the events from the watcher.

inotify: rename handle_event to handle_pollevent to avoid confusion event here refers to poll events, and are different from events read in server.read_events for example, where those events are inotify events.