[Tails-dev] [review'n'merge:1.4] bugfix/6073-cleanup-package…

Hi,

this branch finally implements a bunch of cleanups that I've been
postponing for a while. Please merge into devel (and stable if you
feel like it).

My diff results can be found on
https://labs.riseup.net/code/issues/6073#note-9 -- but I didn't bother
running the automated test suite on the resulting ISO.

Cheers,
--
intrigeri