Minor lispintro tweaks

Minor lispintro tweaks

* doc/lispintro/Makefile.in (emacsdir): New variable..
(MAKEINFO_OPTS, ENVADD): Add $emacsdir.
(srcs): Add emacsver.texi.
(dist): Include emacsver.texi.  Edit emacsdir.

* doc/lispintro/emacs-lisp-intro.texi (emacsver.texi): Include it.
(copying): For non-printed versions, uses Emacs version rather
than that of the printed book.
(Complications, Lisp macro, defvar and asterisk, defcustom): Copyedits.

* doc/lispintro/makefile.w32-in (emacsdir): New variable.
(INFO_SOURCES): Add emacsver.texi.
(ENVADD): Add $emacsdir (and $texinfodir).