Make some variable aliases obsolete

Make some variable aliases obsolete

* lisp/progmodes/make-mode.el (makefile-query-one-target-method):
* lisp/skeleton.el (skeleton-transformation, skeleton-filter):
* lisp/textmodes/artist.el (artist-text-renderer):
* lisp/textmodes/bibtex.el (bibtex-autokey-name-case-convert):
(bibtex-autokey-titleword-case-convert):
* lisp/textmodes/ispell.el (ispell-format-word):
* lisp/textmodes/sgml-mode.el (sgml-transformation):
* lisp/vc/add-log.el (change-log-time-zone-rule): Make variable
aliases obsolete.