Remove version numbers for some built-in packages?

[Stefan Kangas]

It seems like the package versions in built-in packages sometimes
change very rarely.  For example, checkdoc.el has had the same version
number since 1998.  An extreme example is edmacro.el, which has had
the same version number since 1993.  Yet if you run M-x
finder-by-keyword, the version number will be displayed next to the
package name like it actually means something.

It seems to me that having no version number in the library would make
more sense in these cases.  It's part of Emacs and has whatever
version Emacs has.  Also having no version would clarify which
packages might have a more recent version available elsewhere.

So speaking of version numbers of built-in packages, which are not
available from ELPA or elsewhere, and maintained only in our own tree:

1. Do we need a version number in the header for these cases?

2. Do the 'foobar-version' variables serve any purpose whatsoever (in
these cases), or should they just be declared obsolete?  Maybe they
were useful at one point, but they're hardly useful when the values
haven't changed in 15+ years.

Some examples of the packages I'm talking about:
- checkdoc
- delim-col
- edmacro
- hippie-exp
- woman
- edt

Some examples of packages I'm *not* talking about:
- org-mode
- cc-mode
- ada-mode

To be clear, I'm *not* talking about any package available also from
ELPA, has an active maintainer to make the decision, or where the
version number has changed some time during the previous decade.  I
would suggest to clean up only the most obvious candidates.

Best regards,
Stefan Kangas