Set the version number in the texinfo manuals using configure

[Eli Zaretskii]

IMO, the changes introduced with revno 101857 do more trouble than
the problem they are supposed to solve.

I understand the need to ease the maintenance burden, and support the
measures to do so.  But I think the means chosen in this case are not
well thought out, to say the least.  For starters, this breaks the
Windows build:

  make[1]: Entering directory `D:/gnu/bzr/emacs/trunk/doc/emacs'
  makeinfo --force emacs.texi
  emacs.texi:8: @include `emacsver.texi': No such file or directory.
  emacs.texi:32: warning: undefined flag: EMACSVER.
  emacs.texi:102: warning: undefined flag: EMACSVER.
  emacs.texi:113: warning: undefined flag: EMACSVER.
  D:\gnu\bzr\emacs\trunk\doc\emacs//anti.texi:12: warning: undefined flag: 
EMACSVER.
  make[1]: *** [../../info/emacs] Error 1
  make[1]: Leaving directory `D:/gnu/bzr/emacs/trunk/doc/emacs'
  make: *** [info-gmake] Error 2

What's worse, I don't know how to solve this cleanly without requiring
the end users to have a port of Sed installed.  That's because the way
emacsver.texi gets created is by using a string generated by the
configure script that edits src/emacs.c with Sed.

More importantly, I don't understand what is the plan here.  Are we
going to introduce similar handling into all the other places where
the version string is used?  If not, why bother with this one alone,
when we already have a Lisp program to update them all when a release
is tarred?

If we are going to do something similar in other places, then let's
devise a machinery that could be easily ported to non-Posix platforms,
because at least some of these places are specific to those platforms.
Such changes should be at least discussed first and the blueprints
posted, to make sure all the aspects are understood and solutions
exists on all supported platforms.

I actually don't understand what's wrong with admin/admin.el that
requires to change the way we set version strings in the files that
need it.  If there are any disadvantages in admin.el, can they be
spelled out, please?

In addition, these changes have 2 smaller problems:

 . the file emacsver.texi.in violates the file-name restrictions on
   DOS filesystems, so it should be renamed to something like
   emacsver.in

 . the changes remove the arch-tag from several files -- what is the
   story here?