Almost final version of v.1.0 of redesigned Polymer UI

- Menu doesn't drop down when the button is clicked (but can be forced to display in DevTools)
- Menu doesn't look nice
- Dialogs don't pop-up when a respective menu item is clicked
- Item order in the menu is not as wanted

Many of these are not critical anyway, as the UI will be further redone in a more Polymer-y way:

- Prepare data and event handlers in the app and pass it to elements, which display it as appropriate.
- Dialogs, menus etc. will be completely replaced by respective Spark widgets.