Move 'categories' to 'pseudo-dependency-lists' and rename categories.

The categories now contain the 'archtrack-' prefix. Before, the prefix
was added in the PKGBUILD generation process.
Remove the build function from rfidiot.

It wasn't used anyways.
Remove ferret from the sniffing-spoofing category.

This package is a mess. I'm going to contact its maintainer to see if
he'll clean it up.
Update README.