bug#20834: 25.0.50; install-autoremove cycle with the tablist package

[Artur Malabarba]

> Does that explain something?  E.g., package-autoremove only works with
> the declared dependencies whereas a package upgrade will also recognize
> that (featurep 'tablist) is true in the currently running emacs which
> means it is actually used and thus it must be installed again?

When checking what is or isn't needed Package.el only looks at
PackageRequires declarations, so that explains why package.el told you
to autoremove it. When pulling in packages, it also only downloads
declared dependencies, so it doesn't explain how tablist was installed
for you in the first place.

AFAIK, package.el only ever cares about what's written on
PACKAGENAME-pkg.el files, which are generated from PackageRequires
(among other information) at installation.