Manager now fires stop-related events

Gives more fine-grained control as to when the actual event fires.  We also give a small bit of time for the event processors to take effect for those handlers with asynchronous side effects (like shutting down other threads and subsystems).

lib/sidekiq/cli.rb

@@ -97,7 +97,6 @@ def run
       rescue Interrupt
         logger.info 'Shutting down'
         launcher.stop
-        fire_event(:shutdown, true)
         # Explicitly exit so busy Processor threads can't block
         # process shutdown.
         exit(0)
@@ -134,7 +133,6 @@ def handle_signal(sig)
       when 'USR1'
         Sidekiq.logger.info "Received USR1, no longer accepting new work"
         launcher.quiet
-        fire_event(:quiet, true)
       when 'USR2'
         if Sidekiq.options[:logfile]
           Sidekiq.logger.info "Received USR2, reopening log file"

lib/sidekiq/manager.rb

@@ -52,10 +52,17 @@ def quiet
 
       logger.info { "Terminating quiet workers" }
       @workers.each { |x| x.terminate }
+      fire_event(:quiet, true)
     end
 
     def stop(deadline)
       quiet
+      fire_event(:shutdown, true)
+
+      # some of the shutdown events can be async,
+      # we don't have any way to know when they're done but
+      # give them a little time to take effect
+      sleep 0.5
       return if @workers.empty?
 
       logger.info { "Pausing to allow workers to finish..." }