Add new launcher-partial that works on root level. Cleanup LauncherTemplate (partials, routing, content style)
Re-factor `<pj-dashboard>` to `<body is="launcher-main(-view)">` - component responsible only for visual layout, now all semantic content is clearly stated in LightDOM

Change deprecated polymer-ui-elements to core- and paper- ones.
Move editingMode flag to server-side.
Mock apps list on server as well.