Misc small doc/ Makefile cleanup

Misc small doc/ Makefile cleanup

* emacs/Makefile.in (mkinfodir): Remove.
(.dvi.ps): Replace with pattern rule.
(${buildinfodir}): New rule.
($(buildinfodir)/emacs.info): Use order-only prereq for output dir.  Use $<.
(emacs.dvi, emacs.pdf, emacs.html, emacs-xtra.dvi, emacs-xtra.pdf): Use $<.
(%.ps): New rule.

* lispintro/Makefile.in (mkinfodir): Remove.
(.dvi.ps): Replace with explicit rule.
(${buildinfodir}): New rule.
(${buildinfodir}/eintr.info): Use order-only prereq for output dir.  Use $<.
(emacs-lisp-intro.dvi, emacs-lisp-intro.pdf, emacs-lisp-intro.html): Use $<.
(emacs-lisp-intro.ps): New rule.

* lispref/Makefile.in (mkinfodir): Remove.
(.dvi.ps): Replace with explicit rule.
(html): Declare as PHONY.
(${buildinfodir}): New rule.
($(buildinfodir)/elisp.info): Use order-only prereq for output dir.  Use $<.
(elisp.dvi, elisp.html, elisp.pdf): Use $<.
(elisp.ps): New rule.