Instead of querying, use Kotti's .children attribute. Not sure
on the speed (in my case it was very marginally faster this
way - around 0.1s with 3000 entries when running in
development mode while using sqlite) - when we succesfully
use caching, this should be faster.
Put all filtering in one function so we only need to iterate
once.
Cleaning up imports
Fixes to archives and categories view templates
Minor cleaning
If you choose 0 in the "how many categories/archives are
shown" option, it shows all (updated the description of
settings too)