bug#11410: 24.1.50; package.el `emacs' package information is broken

[Stefan Monnier]

> The Elisp manual "Conventional Headers for Emacs Libraries" node says:
>     The package code automatically defines a package named `emacs'
>     with the version number of the currently running Emacs.  This can
>     be used to require a minimal version of Emacs for a package.

BTW I highly doubt the usefulness of such a dependency.  Package.el can
use dependencies to automatically download&update needed packages, but
it currently can't do that for `emacs', and in general it's can't do
that at all (the same set of installed packages might even be used by
different versions of Emacs).

So such a dependency makes more sense as a load-time test (written in
Elisp directly in the package's code) rather than as
a package.el dependency.


        Stefan