pmb.chroot.apk.installed() used to return only the explicitly installed
packages. This is not good enough for the initfs check functions (and
especially for the "lazy reproducible builds", from which branch this
commit was cherry picked).
This commit introduces more noise for the logfile - if this becomes
a problem, raise your voice in the issues tracker and we'll do something
about it.
(This commit also changes minor code styling in other files, I did
not run autopep8 last time, because flake8 didn't complain...)
Oliver Smith