Merge branch 'jk/fsmonitor-event-listener-race-fix'

On macOS, fsmonitor can fall into a race condition that results in
a client waiting forever to be notified for an event that have
already happened.  This problem has been corrected.

* jk/fsmonitor-event-listener-race-fix:
  fsmonitor: initialize fs event listener before accepting clients
  simple-ipc: split async server initialization and running