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