fixes #1 - DRY, reuse Knife::Core::ObjectLoader
fixes #1 - DRY, reuse Knife::Core::ObjectLoader

* Add loader method to create instance of ObjectLoader
* Use loader.find_all_objects for determining the entries in the role_path
* Use loader.load_from to load roles in the role_path

miketheman/knife-role-spaghetti,philoserf/knife-role-spaghetti