Squashed commit of the following:

commit 454b5944d38e3971b8c90c23aa948040a04245b1
Author: emiko <tamiya.emiko@miraitsystems.jp>
Date:   Mon Feb 24 02:01:21 2014 +0900

    version 2.0

commit 4f8d83a5b9faf08e14c153d540038c66a2722f51
Author: emiko <tamiya.emiko@miraitsystems.jp>
Date:   Sun Feb 23 23:16:47 2014 +0900

    Gemfile for version 2.0

commit fbe76386b0cd77e720ef65bd30ba22a51a3cebb2
Author: emiko <tamiya.emiko@miraitsystems.jp>
Date:   Sun Feb 23 23:07:43 2014 +0900

    refs 6610 PurchaseRequest-Order(order_list) relationship is of no use

commit 9d90213f30abf2590184dad20d53e66f0145acaf
Author: emiko <tamiya.emiko@miraitsystems.jp>
Date:   Sun Feb 23 20:52:46 2014 +0900

    refs 6612 migration file to add checked_at

commit aca561dfd9fe3a1335546ad9b3e2d430c9782ec3
Author: emiko <tamiya.emiko@miraitsystems.jp>
Date:   Sun Feb 23 19:46:09 2014 +0900

    refs 6518 rename Patron model to Agent

commit 5278cd6b8d52ee0a7807af280f2979c7251a059f
Author: emiko <tamiya.emiko@miraitsystems.jp>
Date:   Sun Feb 23 00:01:47 2014 +0900

    Gemfile for version t.1.4.2 before rename Patron model to Agent
refs 6486 nacsisインポート機能の修正