A variety of fixes

* most important: refactor Directive and System to use proper subclassing  - includes a migration to transform polymorphic types to use the correct    "type"  - includes a variety of test/behave changes to handle inheritance cases  - permissions for inherited types also inherit (!)  - fix admin/reindex to not duplicate entries due to inheritance* merged in quick-search refinements and mapping refinements from Brad* several fixes for dashboard layout, including:  - remove widget default heights  - .widget-area sizing