* Add Kanban-compatible stage model base.kanban.stage
* Add views, menu items, actions, and access controls needed to manage base.kanban.stage records
* Add abstract model base.kanban.abstract that other models can inherit from to gain Kanban stage functionality
* Add base Kanban view base_kanban_abstract_view_kanban, which can be customized as needed for use with models that inherit from base.kanban.abstract
* Add model base.kanban.abstract.tester, which is needed for base.kanban.abstract unit tests