Public views refactor

- New public header for all public pages.
- Using same layout for public_map and embed_map.
- Using same layout for password protected views.
- Using same layout for public_dashboard view (datasets and visualizations) and used for regular and organization profiles.
- Reviewed all public views and JS and CSS resources are separated.
- Twitter cards for all public pages added.
- Fixed problem with bad html indentation in public_dashboard.
- Reviewed views for IE browsers (IE7 - IE11).
- Reviewed views for mobile and tablet devices.


why don't you use Rails' "api_v2_visualizations_vizjson_url" or "api_v2_visualizations_vizjson_path"? I dislike hand-crafted urls, after multiuser the more we can rely on a single point of url generation (Rails and routes.rb) the better