Switching from my custom, brittle, styling implementation `styler` to
the wonder `flavours` program which does exactly the same only with more
clarity, faster and - I would presume - more stable.
Split the lists into two, with testing getting automatically updated on
packages added (and removed, but only if the package to be removed is
*not* in stable packages already).
This way, I can always be sure that I have my stable setup in the
repository, but packages that I am temporarily testing have a place
without being forgotten and I can more easily change them around until
they find a place in stable or get thrown out.