Some minor fixes for my packages - ktap, cb0cat, etc

This contains some amendments to my packages:

 * Updates `ktap` (which adds a useful new library), and fixes the i686 build - since the FFI is not available yet. This is now controlled by a `useFFI` attribute.
 * Specifies the `cb0cat` platform to be `unix` so binaries will be built by Hydra
 * Adds a homepage to `checksec`, and removes some whitespace.