(#15) Replace basic navigation with ui.rooter

- @todo: reimplement history
(#15) Reimplemented add/edit nav
(#15) Reimplemented breadcrumbs

- temporarily disabled: nav history
(#15) Basic reimplementaiton of nav history

- not working at the moment
(#15) Making undo and redo work with history
(#15) Basic sref for breadcrumbs