Integrate blocking and multiplexing workers usage

lib/uh/wm/cli.rb

@@ -77,6 +77,11 @@ module Uh
           opts.on '-l', '--layout LAYOUT', 'specify layout' do |layout|
             @env.layout_class = self.class.const_get layout.to_sym
           end
+
+          opts.on '-w', Workers.types, '--worker WORKER',
+            'specify worker' do |worker|
+            @env.worker = worker.to_sym
+          end
         end
       end
     end

lib/uh/wm/runner.rb

@@ -73,7 +73,9 @@ module Uh
       end
 
       def run_until &block
-        manager.handle_pending_events until block.call
+        worker.watch @manager
+        @env.log "Working events with `#{worker.class}'"
+        worker.work_events until block.call
       end
 
       def terminate