Adding links to products in rankings

Ideally should point to the product’s page, but does not exist yet.
Link products to product page
Adding links and icons to country pages links
Fixing iframe links
Fixed links
Fixed #220
Disable import button for some apps

E.g. apps only using export such as product_space and pie_scatter
Fixes for pie scatter
Done #121 but remains related issue #181
Widget buttons for 1y 5y growth in treemap #222
Removed duplicate files
Default callback for tree map color
Progress on diff visualization
Fixes on home page + progress search integration
Add in snippet to explore page to log errors for selenium / phantomjs
Remove functionality that creates a data table for now since it isn't
even exposed to the user.
Completed search box integration in home page
Adding caption for size encoding in pie_scatter
Fixed map slider
Refactored highlight functions now in indep. file