Cache update

f? 

The only issue is if you do a 'Clear Cache' then  a 'Download All Documents' without viewing the home page again, it only caches the default topics (there's 4 of them) from the front page. This is because it looks in the database for 'topics:' to find which subtopics it should send off to kitsune to cache.
The promise will resolve before these documents are downloaded. You should wait on both this and the putSet below before resolving.