ライブラリモジュール追記

 Changes to be committed:
	modified:   app/workers/Sitesync_worker.rb
modified:   config/application.rb
new file:   dump.rdb
new file:   lib/diff_merge.rb
 Changes not staged for commit:
	modified:   dump.rdb
タイムスタンプを比較して差分更新
	deleted:    dump.rdb
	modified:   lib/diff_merge.rb