Add a cross to the brew column if it is not in the shipped-list
Add some legend to let user know what tick and cross mean
Preliminary fix for caching. Use some kind of russian doll caching

(Not really).

Switch the caching from a complete view to caching of each package listed in the
table in index.html. The caching of a package will 'expire' once the
'last_updated' column in a package is changed to something newer than it was
before.