Display charts (such as from imdb, blu-ray.com) on home page v2.

This is an updated version of my previous pull request #2590.

Improvements since last time:
- A "refresh now" button for manual updating
- Status text showing "refreshing" while updating the charts
- Remembers your last open tab (suggestions vs charts) by cookie
- Home page much faster to load since we won't wait until charts fetched
- Each chart now has a permanent placement (previously they would be placed randomly after an update)

Of course it has also been updated to work with latest develop-branch. All in all, I think it is pretty solid now.

More chart sources can easily be added later on, but before spending more time I wanted to check out the response on what I already have :)