Added a debug message when running run_on_change

So the debug mode is a little more useful...

Also added timestamp in debug print

lib/guard.rb

@@ -43,7 +43,10 @@ module Guard
     def run_on_change_for_all_guards(files)
       guards.each do |guard|
         paths = Watcher.match_files(guard, files)
-        supervised_task(guard, :run_on_change, paths) unless paths.empty?
+        unless paths.empty?
+          UI.debug "#{guard.class.name}#run_on_change with #{paths.inspect}"
+          supervised_task(guard, :run_on_change, paths)
+        end
       end
 
       # Reparse the whole directory to catch new files modified during the guards run

lib/guard/ui.rb

@@ -26,7 +26,7 @@ module Guard
       def debug(message, options = {})
         unless ENV["GUARD_ENV"] == "test"
           reset_line if options[:reset]
-          puts "DEBUG: #{message}" if ::Guard.options && ::Guard.options[:debug]
+          puts "DEBUG (#{Time.now.strftime('%T')}): #{message}" if ::Guard.options && ::Guard.options[:debug]
         end
       end