* Create "Runner" class
* Adapt Runner class
* Add "DeepRunner" class
* Fix bug in Runner#new ("@config.token" to "config.token")
* @options.config receive Config.new
   * In order to reduce the arguments to be passed to the runner
* Add new class "SearchProxy"
* Add new proxies "grep", "simple"
* Copy "searcher.rb" to "simple.rb"
* Require "SearchProxy" class
* Strip down to "Simple" class for the funtions
* Separate "ItemExtention" module
* Add new method "grep_options?"
* Add proxy method
* Create "SearchProxy" of Grep
   * define getter @pattern to "Simple"
* Enable to receive the option