ispell.el: Extend to aspell current hunspell handling of aliases names for standard...

ispell.el: Extend to aspell current hunspell handling of aliases names for standard dicts.

Extend `ispell-hunspell-dictionary-equivs-alist' use to aspell, once
renamed to a more general `ispell-dicts-name2locale-equivs-alist' name.

Originally reported as http://bugs.debian.org/745613

* textmodes/ispell.el (ispell-dicts-name2locale-equivs-alist)
	(ispell-hunspell-fill-dictionary-entry)
	(ispell-find-hunspell-dictionaries)
	(ispell-set-spellchecker-params): New generic name for
	`ispell-hunspell-dictionary-equivs-alist'.
	(ispell-aspell-add-aliases): Also use
	`ispell-dicts-name2locale-equivs-alist' to get aspell aliases for
	standard dict names.